System for scalable control and reading of QUBITS

Abstract

System for controlling and reading qubits, wherein the system comprises: a first lossless microwave switch directly connected to a quantum system; a second lossless microwave switch; and a quantum-limited amplifier directly connected to the second lossless microwave switch, wherein the system further comprises a circulator connecting the first lossless microwave switch to the second lossless microwave switch.

Description

BACKGROUND

[0001] The present invention relates to superconducting electronic units and in particular a scheme for scalable control and readout of qubits.

[0002] In circuit quantum electrodynamics, quantum data processing uses nonlinear superconducting units called qubits to process and store quantum information at microwave frequencies. Resonators (e.g., a two-dimensional (2D) planar waveguide or a three-dimensional (3D) microwave cavity) are used to read out qubits and enable interaction between them. For example, each superconducting qubit can contain one or more Josephson junctions connected in parallel to the junctions by capacitors. The qubits are capacitively coupled to the resonators (e.g., 2D or 3D microwave cavities). SUMMARY

[0003] According to one or more embodiments, a system for driving and reading qubits is provided. The system includes a first lossless microwave switch connected to a quantum system, a second lossless microwave switch that can be connected to the first lossless microwave switch, and a quantum-limited amplifier that can be connected to the second lossless microwave switch.

[0004] According to one or more embodiments, a system for driving and reading qubits is provided. The system includes a first lossless microwave switch connected to a quantum system, to which a first input can be connected, and a quantum-limited amplifier can be connected. The system also includes a second lossless microwave switch connected to the quantum system, to which a second input can be connected. The second input is configured for driving the quantum system, and the first input is configured for reading the quantum system.

[0005] According to one or more embodiments, a system for driving and reading qubits is provided. The system includes a lossless microwave signal distributor connected to a quantum system, to which a first input can be connected. The system includes a lossless microwave switch connected to the quantum system, to which a second input can be connected. The second input is configured to drive the quantum system via the lossless microwave switch, and the first input is configured to read the quantum system via the lossless microwave signal distributor.

[0006] According to one or more embodiments, a system for driving and reading qubits is provided. The system includes a lossless microwave signal distributor connected to a quantum system, with a first input connected to the lossless microwave signal distributor. The system includes a lossless microwave switch connected to the quantum system, with a second input that can be connected to the lossless microwave switch. The second input is configured to drive the quantum system via the lossless microwave switch. The system also includes a lossless microwave signal combiner connected to the quantum system, with the first input configured to read the quantum system via the lossless microwave signal distributor and the lossless microwave signal combiner. List of characters Fig. Figure 1 is a schematic representation of a superconducting microwave switch / router according to one or more embodiments. Fig. Figure 2 is a block diagram of the superconducting microwave switch / router from Fig. 1 according to one or more embodiments. Fig. Figure 3 is a schematic representation of the superconducting microwave switch / router, illustrating transmit as an operating mode according to one or more embodiments. Fig. Figure 4 is a schematic representation of the superconducting microwave switch / router, illustrating reflection as the operating mode according to one or more embodiments. Fig. Figure 5 is a schematic representation of a superconducting microwave switch / router according to one or more embodiments. Fig. Figure 6 is a block diagram of the superconducting microwave switch / router from Fig. 5 according to one or more embodiments. Fig. Figure 7 is a schematic representation of a superconducting microwave switch / router according to one or more embodiments. Fig. Figure 8 is a schematic representation of a superconducting microwave switch / router from Fig. 1 according to one or more embodiments. Fig. Figure 9 is a schematic representation of a superconducting microwave switch / router with N terminals according to one or more embodiments. Fig. Figure 10 is a schematic representation of a unit illustrating a microwave combiner for quantum signals according to one or more embodiments. Fig. Figure 11 is a schematic representation of a unit showing a microwave distributor for quantum signals according to one or more embodiments. Fig. 12 is a system that shows the unit used in a quantum system application according to one or more embodiments. Fig. Figure 13 illustrates units as a cascade tree of power combiners according to one or more embodiments. Fig. Figure 14 is a schematic representation of the unit illustrating a microwave combiner for quantum signals according to one or more embodiments. Fig. 15 is a system for controlling and reading qubits according to one or more embodiments. Fig. 16 is a system for controlling and reading qubits according to one or more embodiments. Fig. 17 is a system for controlling and reading qubits according to one or more embodiments. Fig. 18 is a system for controlling and reading qubits according to one or more embodiments. Fig. 19 is a flowchart of a procedure for configuring a system of Fig. 15 for controlling and reading qubits according to one or more embodiments. Fig. 20 is a flowchart of a procedure for configuring a system of Fig. 16 for controlling and reading qubits according to one or more embodiments. Fig. 21 is a flowchart of a procedure for configuring a system of Fig. 17 for controlling and reading qubits according to one or more embodiments. Fig. 22 is a flowchart of a procedure for configuring a system of Fig. 18 for controlling and reading qubits according to one or more embodiments. DETAILED DESCRIPTION

[0007] Various embodiments are described here with reference to the accompanying drawings. Alternative embodiments may be developed without exceeding the scope of this document. It is noted that various connections and positional relationships (e.g., above, below, next to, etc.) between elements are specified in the following description and in the drawings. These connections and / or positional relationships may be direct or indirect unless otherwise specified and are not intended to be restrictive in this respect. Accordingly, a connection between entities may refer to a direct or an indirect connection, and a positional relationship between entities may be a direct or an indirect positional relationship. As an example of an indirect positional relationship, references to forming layer "A" above layer "B" include situations where one or more intermediate layers (e.g.,a layer “C”) lies between a layer “A” and a layer “B” as long as the relevant properties and functionalities of layer “A” and layer “B” are not significantly changed by the intermediate layer(s).

[0008] The electromagnetic energy associated with the qubit is stored in the Josephson junctions and in the capacitive and inductive elements that comprise the qubit. In one example, to read the qubit state, a microwave signal is applied to the microwave readout cavity, coupling to the qubit at the cavity frequency corresponding to the qubit state. The transmitted (or reflected) microwave signal passes through several thermal isolation stages and low-noise amplifiers, which are necessary to eliminate or reduce noise and improve the signal-to-noise ratio. The microwave signal is measured at room temperature. A returned high microwave signal indicates that the qubit is in a high state, and a low microwave signal indicates a low state.Microwave readout provides a stable signal amplitude for control, and off-the-shelf (COTS) standard hardware is available that covers most microwave frequency ranges.

[0009] Quantum systems such as superconducting qubits are highly sensitive to electromagnetic interference, particularly in the microwave and infrared ranges. To protect these quantum systems from microwave and infrared interference, several layers are used for filtering, attenuation, and insulation. Of particular interest are the protective layers used on the input and output lines (I / O lines), also known as transmission lines, which are connected to the quantum system and carry the input and output signals to and from it. In superconducting qubits, these I / O lines (transmission lines) are typically microwave coaxial cables or waveguides.Some of the techniques or components used to eliminate or attenuate noise propagating in or entering these transmission lines include attenuators, circulators, isolators, low-pass microwave filters, band-pass microwave filters, and infrared filters based on lossy absorption materials. However, these noise isolation components and microwave signal amplification techniques require a significant amount of additional microwave hardware and incur additional costs.

[0010] Now, let us consider aspects of the present invention according to one or more embodiments, wherein superconducting (or lossless) microwave switches / routers enable the on-demand routing of quantum signals between different nodes of a circuit or between different terminals. Superconducting microwave switches can have many applications in the field of quantum information processing. For example, superconducting microwave switches can be used for time-division multiplexed readout, time-division multiplexed drive (e.g., cross-resonance drive), time-division multiplexed characterization of multiple units, time-division multiplexed interaction between pairs of quantum systems, time-dependent signal circulation, etc.

[0011] According to one or more embodiments, a superconducting microwave switch is provided, which may have one input terminal and N output terminals. The superconducting microwave switch may also have one output terminal and N input terminals. All terminals of the superconducting microwave unit are designed to have the same characteristic impedance Z0. In one implementation, each input-output pair is connected via a tunable low-pass filter, the cutoff frequency of which can be adjusted locally using an applied magnetic flux. The tunable low-pass filter can be implemented using a chain of series inductive elements (e.g., DC superconducting quantum interference devices (SQUIDs)) and capacitive shunt elements (e.g., lumped-element capacitors).In another implementation, each input-output pair can be connected via a tunable high-pass filter whose cutoff frequency can be set locally by applying a magnetic flux, and the tunable high-pass filter can be implemented using series capacitive elements (e.g., lumped element capacitors) and inductive shunt elements (e.g., DC-SQUIDs).

[0012] Now to a more detailed description of aspects of the present invention, wherein Fig. 1. A schematic representation of a superconducting microwave switch / router 100 according to one or more embodiments. Fig. Figure 1 illustrates the components of the superconducting microwave switch / router 100 based on a tunable filter 20 In this example, the tunable filter is... 20about a tunable low-pass filter (TLPF). However, it is understood that embodiments are not limited to low-pass filters, as will be explained below.

[0013] In this example, the superconducting microwave switch / router contains 100 Connections 10 , such as connections 1 and 2 The connections 10 These are input and output connections. The tunable filter 20 contains one or more unit cells 60 Each unit cell 60 includes an adjustable coil 40 , which is referred to as the variable inductive element L1 (and other examples include L2, L3 and DC-SQUIDs, which are discussed below), and each unit cell 60 contains a capacitor 50 , which is referred to as the capacitive element C. In each unit cell 60 The adjustable coil L1 40 is in series with the connections 10connected, and a capacitor C 50 is connected to one end of the variable coil 40 and connected to mass. There is a number N of unit cells. 60 , which apply to a total of N unit cells in the tunable filter 20 repeat and are connected to each other (in series). For N unit cells, the coils L1 40 are connected in series, with a corresponding capacitor at each coil L1 40. 50 is switched to ground. The connection of the terminals 10 , the adjustable coils L1 40 and the capacitors C 50 are connected via the transmission line 30 The transmission line 30 acts as a superconducting wire or waveguide to transmit a microwave signal from the connection 1 via the tunable filter 20 for connection 2 or vice versa. A coaxial cable can be used with the outer ends of the connectors. 10The two cables must be connected so that one coaxial cable inputs microwave signals and another coaxial cable outputs the microwave signals. The transmission line 30 It could be a stripline, a microstrip, etc. The variable coils 40 , the capacitors 50 and the transmission lines 30 They are made of superconducting material. Examples of superconducting materials (at low temperatures, such as 10 to 100 millikelvin (mK) or about 4 K) include niobium, aluminum, tantalum, etc.

[0014] Fig. Figure 2 is a block diagram of the superconducting microwave switch / router. 100 from Fig. 1 according to one or more embodiments. Fig. 2 is an equivalent circuit of Fig. 1., without the internal details of the tunable filter 20 to represent.

[0015] It can be assumed that the microwave signal passing through the superconducting microwave switch / router 100 The signal to be transmitted has a center angular frequency ω0. The impedance designation Z0 is the characteristic impedance at the terminals. 1 and 2 (which can be the input and output terminals, or vice versa). For example, the characteristic impedance Z0 at each terminal can be 50 The value is ohms (Ω).

[0016] For a single unit cell 60 is the impedance Z1, where Z 1 = L 1 C and where the angular frequency ω1 of the unit cell 60 ω 1 = 1 C L 1 is the cutoff frequency of the tunable filter. 20 , which are called ω CThe value denoted is on the order of the resonance angle frequency ω1 of the unit cell (or several unit cells joined together) and correlates with ω1, which means that ω C as ω1 increases and decreases. The exact dependence of the value of ω C The value of ω1 and the number of unit cells N can be found by microwave simulation or calculation. It follows that the cutoff frequency ω C of the tunable filter 20 from the values ​​of the variable coil L1 40 and the capacitor C 50 (for the one or several elementary cells) 60 ) depends. In particular, the inductance of the variable coil L1 40 controls the cutoff frequency ω. C of the tunable filter 20 , which controls when the tunable filter is activated 20with respect to the microwave signal (center angular frequency ω0) in transmit or reflection mode. The inductance of the variable coils L1 40 has an inverse relationship to the cutoff frequency ω C . If, for example, the inductance of the variable coil L1 is increased to 40, the cutoff frequency ω decreases. C of the tunable filter. Conversely, if the inductance of the variable coil L1 40 As the cutoff frequency is reduced, the cutoff frequency ω becomes smaller. C of the tunable filter 20 larger. It is noted that varying the inductance of the unit cell changes not only the cutoff frequency of the filter but also its characteristic impedance. Therefore, it may be desirable for Z1, or the characteristic impedance of the filter, to match the characteristic impedance of the terminals as closely as possible when the switch is closed, i.e., operating in transmission mode.

[0017] Therefore, if operation occurs with the switch closed, the superconducting microwave switch / router will 100 controlled in such a way that it transmits the microwave signal (center angle frequency ω0) from the port 1 for connection 2 (or vice versa) by reducing the inductance of the variable coil L1 40 in the tunable filter 20 This allows the microwave signal (center angle frequency ω0) to pass through into the low-pass band of the tunable filter. 20 falls. When operating as an open switch, the superconducting microwave switch / router 100 controlled in such a way that it prevents the transmission of the microwave signal (center angle frequency ω0) from the connection 1 for connection 2 (or vice versa) by increasing the inductance of the variable coil L1 40 in the tunable filter 20The signal is blocked using reflection. This allows the microwave signal (center angle frequency ω0) to lie outside the low-pass range and thus be attenuated or, in other words, reflected.

[0018] Fig. Figure 3 is a schematic representation of the superconducting microwave switch / router. 100 , illustrating the transmission operating mode according to one or more embodiments. In Fig. 3 is the tunable filter 20 so tuned that the center angular frequency ω0 of the microwave signal arriving through the connection of the unit is 305 is smaller than the cutoff frequency ω C of the tunable filter 20 , i.e. ω0 < ω C In this operating mode, the tunable filter 20 configured to operate in transmission mode, since the frequency of the microwave signal 305 lower than the cutoff frequency of the tunable low-pass filter20 is. Under this condition, the microwave signal 305 from the connection 1 via the tunable filter 20 for connection 2 sent, so that the microwave signal 305 as desired.

[0019] Fig. Figure 4 is a schematic representation of the superconducting microwave switch / router. 100 , which illustrates the reflection operating mode according to one or more embodiments. In Fig. 4 is the tunable filter 20 tuned so that the center angular frequency ω0 of the microwave signal 305 greater than the cutoff frequency ω C of the tunable filter 20 is, i.e. ω0 > ω C In this operating mode, the tunable filter 20 configured to operate in reflection mode, since the frequency of the microwave signal 305 greater than the cutoff frequency of the tunable low-pass filter20 is. Under this condition, the microwave signal 305 , if it is through the connection 1 enters, prevented from joining 2 to get there, since the tunable filter 20 the microwave signal 305 reflected, thereby altering the microwave signal 305 not from the connection 1 for connection 2 can be reached.

[0020] Fig. Figure 5 is a schematic representation of a superconducting microwave switch / router. 100 according to one or more embodiments. Fig. Figure 6 is a block diagram of the superconducting microwave switch / router. 100 from Fig. 5 according to one or more embodiments. Fig. 6 is an equivalent circuit to Fig. 5, without revealing the internal details of the tunable filter 20 be depicted. Fig. 5 and Fig. 6 are analogous to the Fig. 1 and Fig. 2 with the exception that the Fig. 5 and Fig. The number of ports has been increased from 6 to 3 instead of 2. It is understood that this is a superconducting microwave switch / router. 100 It can be expanded to a number of N connections if required.

[0021] In the Fig. 5 and Fig. The configuration shown in section 6 includes two tunable filters. 20 Available. A tunable filter. 20 is between connection 1 and connection 2 switched, while the other tunable filter 20 between connection 1 and connection 3 is switched on. Each of the tunable filters 20 consists of one or more unit cells 60 formed as explained above. For explanatory purposes, the one or more variable coils are shown. 40 as L2 in the tunable filter 20 characterized by the connection between the terminals 1and 2 is switched while one or more variable coils are switched on 40 as L3 in the tunable filter 20 be marked that the connections 1 and 3 is switched on. The tunable filters 20 between the connections 1 and 2 or the connections 1 and 3 They are individually controlled so that one can be operated in transmission mode, while the other is operated in reflection mode.

[0022] The tunable filter 20 between the connections 1 and 2 contains one or more unit cells 60 Each unit cell 60 contains a variable coil L2 40 and a capacitor 50 . In each unit cell 60 The variable coil L2 40 has the following connections: 1 and 2connected in series, and the capacitor C 50 is connected to one end of the variable coil 40 and connected to mass. A number N of unit cells can be used. 60 be present that are contained in the tunable filter 20 for a total of N unit cells between the terminals 1 and 2 repeat and are interconnected. For the tunable filter 20 between the connections 1 and 2 The impedance of each unit cell is Z2, where Z 2 = L 2 C and angular frequency is ω2 where ω 2 = 1 C L 2 .

[0023] Similarly, the tunable filter contains 20 , that between the connections 1 and 3 is switched, one or more elementary cells 60 Each unit cell 60 contains a variable coil L3 40 and a capacitor 50 . In each unit cell 60The variable coil L3 40 has the following connections: 1 and 3 The components are connected in series, and capacitor C50 is connected to one end of variable coil L340 and to ground. There can be N unit cells. 60 be present that are contained in the tunable filter 20 for a total of N unit cells between the terminals 1 and 3 repeat and are interconnected. For the tunable filter 20 , that between the connections 1 and 3 When switched, the impedance of each unit cell is Z3, where Z 3 = L 3 C and the angular frequency is ω3, where ω 3 = 1 C L 3 .

[0024] It goes without saying that additional connections and tunable filters can be added analogously as desired.

[0025] Above, in Fig. 2 the cutoff frequency of the individual tunable filter 20as ω C designated. Since in the Fig. 3 and Fig. 4 more than one tunable filter 20 The tunable filter is intended to be used. 20 , that between the connections 1 and 2 The cutoff frequency is ω when switched. C2 designated, while in the case of the tunable filter 20 , that between the connections 1 and 3 The cutoff frequency is ω when switched. C3 is designated.

[0026] For the operation of the microwave signal 305 during transmission to / between the connection 1 for connection 2 (or vice versa) the tunable filter 20 between the connections 1 and 2 tuned so that the center angular frequency ω0 of the microwave signal 305 is smaller than the cutoff frequency ω C2 of the tunable filter 20 between the connections 1 and2 , while the tunable filter 20 between the connections 1 and 3 is tuned so that the center angular frequency ω0 of the microwave signal 305 much larger than the cutoff frequency ω C3 between the connections 1 and 3 : ω C3 << ω0 < ω C2 In this operating mode, the tunable filter 20 between the connections 1 and 2 configured to operate in transmission mode, since the microwave signal 305 (ω0) smaller than the cutoff frequency ω C2 is, and therefore the microwave signal 305 from the connection 1 through the tunable filter 20 for connection 2 transmitted so that the microwave signal 305 as desired. At the same time, this is between the connections. 1 and 3 switched tunable filters 20configured to operate in reflection mode, since the microwave signal 305 (ω0) greater than the cutoff frequency (ω C3 ) is, and therefore the microwave signal 305 prevented from connecting 1 to connection 3 to get there. Additional conditions for transmission from the connection 1 for connection 2 (or vice versa) includes impedance matching Z2 ≃ Z0. Additional conditions for reflection from / between the terminals are also considered. 1 and 3 Z3 belongs to Z0.

[0027] On the other hand, the operation of the microwave signal requires 305 during transmission to / between the connection 1 for connection 3 (or vice versa) the tunable filter 20 between the connections 1 and 3 tuned so that the center angular frequency ω0 of the microwave signal 305 is smaller than the cutoff frequency ω C3of the tunable filter 20 between the connections 1 and 3 , while the tunable filter 20 between the connections 1 and 2 is tuned so that the center angular frequency ω0 of the microwave signal 305 much larger than the cutoff frequency ω C2 between the connections 1 and 2 : ω C2 << ω0 < ω C3 In this operating mode, the tunable filter 20 between the connections 1 and 3 configured to operate in transmission mode, since the microwave signal 305 (ω0) is smaller than the cutoff frequency ω C3 , and therefore the microwave signal 305 from the connection 1 via the tunable filter 20 for connection 3 transmitted so that the microwave signal 305 as desired. At the same time, this is between the connections.1 and 2 switched tunable filters 20 configured to operate in reflection mode, since the microwave signal 305 (ω0) is greater than the cutoff frequency (ω C2 ), and therefore the microwave signal 305 in this example prevented from connecting 1 to connection 2 to get there. Additional conditions for transmission from the connection 1 for connection 3 (or vice versa) Z3 ≃ Z0 is part of the impedance matching process. Additional conditions apply to reflection from / between the terminals. 1 and 2 Z2 belongs to Z0.

[0028] Fig. Figure 7 is a schematic representation of a superconducting microwave switch / router. 100 according to one or more embodiments. Fig. 7 is analogous to the Fig. 5 and Fig. 6, except that in Fig. 7. The lossless / superconducting microwave switch / router 100 implemented using superconducting direct current (DC) quantum interference units (SQUIDs). In Fig. 7 are all variable coils 40 (explained above) as (variable) DC-SQUIDs 705 in the tunable filter 20 implemented. It is noted that the tunable filters 20 in Fig. 7 are configured to operate in transmission and reflection modes with respect to each of the tunable filters 20 They work as explained above. It is also understood that the superconducting microwave switch / router 100 Depending on requirements, it can be expanded to a number of N connections.

[0029] In the Fig. The configuration shown in section 7 includes two tunable filters. 20 and three connections 10 shown, although more connections 10 and tunable filters20 They can be added analogously. A tunable filter. 20 is between connection 1 and connection 2 switched, while the other tunable filter 20 between connection 1 and connection 3 is switched on. Each of the tunable filters 20 consists of one or more unit cells 60 formed, as explained here

[0030] For the tunable filter 20 , the connection 1 and connection 2 Each unit cell is switched on and contains 60 one or more DC-SQUIDs 705_2. In the unit cell 60 The capacitor connects 50 one or more DC-SQUIDs 705_2 with mass. If more than one DC-SQUID 705_2 is in the unit cell 60When used, the DC-SQUIDs 705_2 are connected in series. A total of M DC-SQUIDs 705_2 can be present per unit cell, where M is an integer of 1 or greater. The tunable filter 20 between the connections 1 and 2 contains one or more unit cells 60 , so that each unit cell 60 with the connections 1 and 2 It is connected in series, and capacitor C50 is connected to one end of the DC-SQUID 705_2 and to ground. In the tunable filter 20 N can be the number of unit cells 60 be, which repeat and are connected in series to create a total of N elementary cells between the terminals 1 and 2 to form, where N is an integer of 1 or greater. For the tunable filter 20 between the connections 1 and 2 The impedance of each unit cell is Z2, where Z 2 = L 2 C and the angular frequency ω2 is, where ω 2 = 1 C L 2 . It should be noted that each DC-SQUID 705_2 has an inductance and / or represents an inductive element, which is designated L2.

[0031] For the tunable filter 20 , the connection 1 and connection 3 Each unit cell is switched on and contains 60 one or more DC-SQUIDs 705_3. In the unit cell 60 The capacitor connects 50 one or more DC-SQUIDs 705_3 with mass. If more than one DC-SQUID 705_3 is in the unit cell 60 When used, the DC-SQUIDs 705_3 are connected in series.

[0032] A total of M DC-SQUIDs 705_3 can be present per unit cell, where M is an integer of 1 or greater. The tunable filter 20 between the connections 1 and 3contains one or more unit cells 60 , so that each unit cell 60 with the connections 1 and 3 It is connected in series, and capacitor C50 is connected to one end of the DC-SQUID 705_3 and to ground. In the tunable filter 20 N can be a number of unit cells 60 for a total of N unit cells located between the terminals 1 and 3 repeat and are connected to each other, where N is an integer of 1 or greater. For the tunable filter 20 between the connections 1 and 3 The impedance of each unit cell is Z3, where Z 3 = L 3 C and the angular frequency ω3 is, where ω 3 = 1 C L 3 . It should be noted that each DC-SQUID 705_3 has an inductance and / or represents an inductive element, which is designated L3.

[0033] Further information on DC-SQUIDs is provided below. A SQUID (Superconducting Quantum Interference Device) is a type of superconducting electronic device known to those skilled in the art. The type of SQUID known as a DC-SQUID, in particular, contains a loop of superconducting wire, superconducting thin-film metal, or other superconducting material, connected by two or more Josephson junctions (JJ). 710 is interrupted. The SQUID contains two or more Josephson transitions. 710in a current-carrying loop. As is generally known to those skilled in the art, the critical Josephson current of the Josephson junctions in the SQUID changes, via the principle of quantum interference of superconducting currents, depending on the magnetic flux passing through the SQUID loop. Similarly, the Josephson inductance exhibited by the Josephson junctions of the SQUID also changes depending on this magnetic flux (which is the magnetic flux Φ2 for each DC-SQUID 705_2 and the magnetic flux Φ3 for each DC-SQUID 705_3). Furthermore, arrays of SQUIDs can be arranged in an electrical circuit such that their inductances are combined.It is stated that the magnetic flux of a loop lying in the plane is a known and precisely defined quantity, including the magnetic field in the loop, multiplied by the cosine of the angle that the field forms with the axis perpendicular to the loop, integrated over the entire area of ​​the loop. Thus, the SQUID is very sensitive to both the magnitude and the direction of the magnetic field in its vicinity (for example, the flux generation line 730_2 generates the magnetic field and thereby causes a magnetic flux Φ2 for each DC-SQUID 705_2, while the flux generation line 730_3 generates the magnetic field and thereby causes a magnetic flux Φ3 for each DC-SQUID 705_3). The DC-SQUID 705_2 and 705_3 are each subjected to the magnetic flux Φ2 and the magnetic flux Φ3 respectively from the magnetic fields generated by the magnetic flux generation line 730_2 and 705_3, respectively.the magnetic flux generation line 730_3 is generated, and thereby its Josephson inductance is changed (the Josephson inductance is measured with L. J2 for DC-SQUID 705_2 and L J3 (designated for DC-SQUID 705_3). For a person skilled in the art, this sensitivity to a magnetic field allows the SQUID to be used as a useful component in an electrical circuit, as changing the Josephson inductance of the SQUID produces useful changes in the circuit's characteristics. The inductances L2 and L3 of the DC-SQUIDs 705_2 and 705_3, respectively, correspond to the Josephson inductance L. J2 for DC-SQUID 705_2 and L J3 For DC-SQUID 705_3. To independently change / control (increase or decrease) the inductance L2 and L3 of the DC-SQUIDs 705_2 and 705_3, magnetic flux generation lines 730_2 and 730_3 are provided. These magnetic flux generation lines can be generally referred to as magnetic flux generation lines. 730The magnetic flux generation lines 730_2 and 730_3 independently apply a magnetic "bias" field perpendicular to the SQUID loop of the respective DC SQUIDs 705_2 and 705_3 to set the "operating point" of the SQUID. Magnetic flux generation line 730_2 has a current I2, which generates a magnetic field to cause the magnetic bias flux Φ2 to change as desired. Similarly, magnetic flux generation line 730_3 has a current I3, which generates a magnetic field to cause the magnetic bias flux Φ3 to change as desired. Accordingly, the tunable filters are 20 between the connections 1 and 2 or the connections 1 and 3 individually controlled, so that one filter can be operated in transmission mode while the other operates in reflection mode.

[0034] The inductance L2 (per unit cell) 60 ) for the tunable filter 20 between the connections 1 and 2 can be considered L2 ≃ ML J2 + L s defined where M is the number of DC-SQUIDS 705_2 in a unit cell, where L J2 the Josephson junction inductance of the DC-SQUID is and where L s the series inductance of the transmission lines 30 (Wires) of each unit cell. The inductance L2 of each unit cell 60 is mainly based on the inductance of the Josephson junction L J2 Therefore, the inductance of the Josephson junction is L J2 defined below (without series inductance L) s the transmission line 30 (Wires): Inductance of the Josephson junction L J 2 = L J 0 | c o s ( π Φ 2 Φ 0 ) | , wobei L J 0 = Φ 0 4 π I 0 , <?page 9=""?> where I0 is the critical current of each Josephson transition 710is, where Φ2 is the magnetic bias flux experienced by the loop, and where Φ 0 = h 2 e is (superconducting magnetic flux quantum), where h is Planck's constant and e is the electron charge.

[0035] Similarly, the inductance L3 (per unit cell) can be 60 ) for the tunable filter 20 between the connections 1 and 3 as L3 ≃ ML J3 + L s defined where M is the number of DC-SQUIDS 705_3 in a unit cell, where L J3 the inductance of the Josephson junction of the DC-SQUID is and where L s the series inductance of the transmission lines 30 (Wires) of each unit cell. The inductance L3 of each unit cell 60 is mainly based on the inductance of the Josephson junction L J3 Therefore, the inductance of the Josephson junction is L J3defined below (without series inductance L) s the transmission line 30 (Wires): Inductance of the Josephson junction L J 0 | c o s ( π Φ 3 Φ 0 ) | , wobei L J 0 = Φ 0 4 π I 0 , where I0 is the critical stream of the (two) Josephson transitions 710 is, where Φ3 is the magnetic bias flux experienced by the loop, and where Φ 0 = h 2 e is (superconducting magnetic flux quantum), where h is Planck's constant and e is the electron charge. In this analysis, the experimentalists assume that the DC-SQUIDs have small loops and that the self-inductance of the DC-SQUID loop is negligible compared to the Josephson inductance of the DC-SQUID.

[0036] It is pointed out that the inductance L2 is the inductance of a unit cell. 60 of N unit cells (N≥1) which are in the tunable filter 20 between the connections 1 and2 is connected in series with the transmission line, and similarly, the inductance L3 is the inductance of an elementary cell. 60 of N unit cells (N≥1) that are in the tunable filter 20 between the connections 1 and 3 is connected in series with the transmission line.

[0037] The person skilled in the art understands that the tunable filter design described here is not limited to identical unit cells with respect to the inductive and capacitive elements in each unit cell. The image of an identical unit cell is presented here mainly for simplification and better understanding. In fact, varying the unit cells based on microwave filter theory can be advantageous and achieve better performance with respect to the maximum amplitude of the ripple in the filter response, the filter flatness, the filter bandwidth, the in-band and out-of-band reflection rate, the attenuation in the stopband, etc. Accordingly, it should be understood that the unit cells may be identical in one or more embodiments in order to exploit one or more of the advantages described above.

[0038] It goes without saying that the superconducting microwave switch / router 100 A configuration can have one input port and N output ports, and / or one output port and N input ports in another configuration. All ports 10 The unit has the same characteristic impedance Z0. Each input / output pair is connected via a tunable low-pass filter whose cutoff frequency can be adjusted locally using the applied magnetic flux. The tunable low-pass filter 20 can be implemented using a chain of inductive elements (DC-SQUIDs) and capacitive elements (condensed element capacitors).

[0039] By controlling the DC currents I2 and I3 through the respective magnetic flux generation lines 730_2 and 730_3, the premagnetization flux values ​​Φ2 and Φ3 can be set independently, which determine the inductance L2 and L3 in each chain. This, in turn, determines the cutoff angular frequencies ω C2 , ω C3 the two tunable filters 20 with respect to ω0 (of the microwave signal) 305 ) so that a path (between the connections) 1 and 2 ) is in transmission mode, while the other path (between the terminals) 1 and 3 ) operates in reflection mode or vice versa.

[0040] For operation in reflection mode (i.e., to block the microwave signal) 305 ) are used with a tunable filter 20 (between the connections 1 and 2 or between the connections 3 and 4) the direct currents I2, I3 are increased to increase the magnetic bias flux Φ2, Φ3 (in one period of the cosine function), which then increases the inductance L2, L3, and thereby the cutoff angular frequency ω C2 , ω C3 reduced. For operation in transmission mode (i.e., for passing through the microwave signal), 305 ) are, conversely, used with a tunable filter 20 (between the connections 1 and 2 or between the connections 3 and 4 ) the direct currents I2, I3 are reduced, and thereby the magnetic bias flux Φ2, Φ3 (in one period of the cosine function) is reduced, which then reduces the inductance L2, L3, and thereby the cutoff angular frequency ω C2 , ω C3 enlarged.

[0041] The DC SQUIDs 705 , the capacitors 50(with the exception of the dielectric material in the capacitors), the magnetic flux generating lines 730 , the transmission lines 30 and the Josephson crossings 710 They are made of superconducting material. Examples of superconducting materials (at low temperatures, such as 10 to 100 millikelvin (mK) or about 4 K) include niobium, aluminum, tantalum, etc. A Josephson junction is a nonlinear element formed from two superconducting metals sandwiching a thin insulator, for example, made of aluminum oxide, niobium oxide, etc.

[0042] Fig. Figure 8 is a schematic representation of a superconducting microwave switch / router. 100 according to one or more embodiments. Fig. 8 is analogous to the Fig. 1 to Fig. 7 with the exception that in this implementation, the tunable filters are 20These are tunable high-pass filters. By using high-pass filters as tunable filters 20 The inductive elements are used. 40 , 705 against the capacitive elements 50 exchanged. Accordingly, the capacitive elements are 50 in series between the terminals 1 and 2 and between the connections 1 and 3 arranged, while the inductive elements 40 , 705 (coil or DC-SQUID) with one end of the capacitive element 50 are connected and then connected to ground. For the transmission of connection 1 after connection 2 (or vice versa) the following condition applies: ω c2 < ω0 << ω c3 For the transmission from the connection 1 for connection 3 (or vice versa), the following condition ω applies. c3 < ω0 << ω c2 .

[0043] Fig. Figure 9 is a schematic representation of a superconducting N-port microwave router. 100 with N ports according to one or more embodiments. The superconducting N-port microwave router 100 The N-terminal interface is generalized / designed in such a way that a connection can be spontaneously established between any pair of terminals. 10 This can be achieved by applying current pulses to the relevant magnetic flux generation lines, which in turn bias the relevant filters to their appropriate flux bias points. At the moment (or nearly the moment) when the microwave signal 305 a connection 10 This can be achieved, for example, by establishing the connection between each pair of connectors. 10 to be manufactured in order to transmit the microwave signal 305 to transmit, while all other connections 10 (via their respective tunable filters) 20 ) the microwave signal 305block. Accordingly, the microwave signal can 305 between each pair of connectors 10 guided by the basic principles discussed here.

[0044] The superconducting microwave router 100 with N connections includes connection 1 , Terminal I, Terminal J to Terminal N. Each of the terminals 1 up to N has its own tunable low-pass filter 20 , so that a single connection 10 with a tunable filter 20 connected to a node 905 is connected. The ones in the Fig. 1 to Fig. The 8 characteristics described in detail apply to Fig. 9 and will not be repeated for the sake of brevity, in order to Fig. 9. Not to be distracted from the essentials. All connections 1 up to N are symmetrical and are based on the same foundation (which differs from the superconducting microwave switches / routers described above). 100differs). To be on the same basis means that the node 905 a central connection point that connects all connections 1 up to N connects, so that each connection 10 its own tunable filter 20 has and that every tunable filter 20 has its own magnetic flux generation line (FL) for tuning its cutoff frequency.

[0045] For example, to transmit the microwave signal 305 To route the signal from terminal N to terminal I, both tunable filters must be used. 20 between terminal N and the node 905 and between terminal I and the node 905 so that they are in transmission mode; at the same time, all remaining tunable filters are 20 They are set to operate in reflection mode. This allows the microwave signal to 305 from terminal N to its tunable filter 20, to the node 905 , to a tunable filter connected to terminal I 20 and then transferred to port I.

[0046] Regarding the node 905 Some technical details will be explained. Generally, the knot should 905 They should be as small as possible for two reasons and ideally concentrated with respect to the wavelengths used in the operation of the unit: 1) to minimize reflections that can limit the transmission of the guided signal, and 2) to connect multiple transmission lines to the node. 905 enable. Furthermore, the ability to connect multiple transmission lines to a common node can 905Connecting them would require the use of (very narrow) high-impedance wires, which in turn might require the tunable filters to have a characteristic impedance that matches the impedance of the connecting lines if the filters are operated in transmission mode (to minimize reflections). Finally, if the characteristic impedance of the tunable filters differs from the characteristic impedance of the unit's terminals, specific matching networks can be designed and integrated between the filters and the unit (to ensure smooth transmission of the propagating signals).

[0047] A method for configuring a lossless / superconducting microwave switch / router 100 It is provided according to one or more embodiments. It can refer to the ones described here. Fig. 1 to Fig. 9 are referred to. A plurality of connections 10 Will be provided. Tunable filters. 20 are provided and are equipped with the connections 10 connected, so that each of the multiple connections 10 a corresponding one of the tunable filters 20 has. The tunable filters 20 are connected with a node 905 (a conductive connection point). A plurality of magnetic flux generation lines (FL) 730 is provided for, so that a single magnetic flux generation line can be formed from the majority of magnetic flux generation lines. 730 a single filter of the tunable filters 20 It tunes one-to-one. A plurality of magnetic sources (such as magnetic flux generating lines, current-carrying wires, tunable magnets, etc.) are arranged such that a single magnetic source from the plurality of magnetic sources selects a single filter from the tunable filters. 20It is a one-to-one match. It should be noted that this picture of a magnetic flux-generating line driving a tunable filter may be a simplification. This is because the response / inductance of the DC-SQUIDs is determined by the total flux passing through their loop, and therefore any change in the current of other magnetic flux-generating lines can fundamentally change the flux bias acting on the DC-SQUID. Of course, the induced flux through the other magnetic flux-generating lines decreases considerably with the distance between them and the DC-SQUID, so experimenters can significantly reduce their contribution by separating them sufficiently.Nevertheless, there may be one or more scenarios where, to adjust the flux bias of a filter, multiple changes can be applied to the currents flowing in nearby magnetic flux generation lines, so that the currents produce the desired flux bias in the various controlled filters.

[0048] According to one or more embodiments, a method for configuring a lossless / superconducting microwave switch / router is described. 100 provided. It can be used for the purposes explained here. Fig. 1 to Fig. 9 are referred to. A plurality of connections 10 is planned. Tunable filters. 20 are compatible with the majority of connections 10 connected, with each connection being from the plurality of connections 10 one of the tunable filters 20 is assigned, with each of the tunable filters 20 a superconducting quantum interference unit705 It contains. Regarding the tunable filters... 20 These could be low-pass filters. Regarding tunable filters... 20 It could be a high-pass filter.

[0049] A method for configuring a lossless / superconducting microwave switch / router 100 is provided according to one or more embodiments. It can refer to the ones described here. Fig. 1 to Fig. 9 are referred to. A node 905 It is intended as a central connection point. Tunable filters. 20 are connected to the node 905 connected, with the tunable filters 20 are configured so that they can be independently tuned to a first state (i.e., transmission mode) in order to receive a microwave signal 305 to transmit, and that they can be independently tuned to a second state (i.e., reflection mode) to transmit the microwave signal 305to lock, so that each of the tunable filters 20 is configured to transmit the signal via the node 905 to any other of the tunable filters 20 can be transferred.

[0050] A method for configuring a lossless / superconducting microwave switch / router 100 is provided according to one or more embodiments. It can refer to the ones described here. Fig. 1 to Fig. 9 are referred to. A plurality of connections 10 is planned. A first pair from the majority of connections. 10 has at least one tunable filter 20 , which is interposed, with the tunable filter 20 is configured to emit a microwave signal 305 transmits. A second pair from the majority of connections. 10 has a different tunable filter 20 , which is interposed, with the other tunable filter20 is configured to reflect the microwave signal.

[0051] The technical effects and advantages include a lossless / superconducting microwave switch / router. Further technical advantages include low attenuation of transmitted signals (<0.05 dB), fast switching (no resonators), for example, in nanoseconds (depending on the mutual inductance between the magnetic flux-generating lines and the SQUIDs), and a relatively large bandwidth (BW) > 280 megahertz (MHz) (which can be significantly improved by allowing certain variations in the unit cells). Another technical advantage is a relatively large on / off ratio (> 20 dB). The lossless / superconducting microwave switch / router can tolerate relatively high powers of > -80 dBm (where 0 dBm corresponds to 1 milliwatt) by adding more SQUIDs and increasing its critical current.The lossless / superconducting microwave switch / router can be manufactured using Nb-Josephson junctions so that it can operate at 4 K, can be designed for any frequency range, and provides a scalable scheme that can be easily extended to 1 input / N outputs (or vice versa).

[0052] Now, let's turn to microwave signal combiners and microwave signal distributors. Microwave signal combiners are used to combine quantum signals in the microwave range, which can lead to impedance mismatches between the terminals (causing reflections), poor isolation between (certain) terminals, and / or the loss of quantum information due to attenuation of the quantum signal. This loss of quantum information can be caused either by internal loss within the power combiner or by a leakage at other terminals. This loss of quantum information can result in a significant reduction in the signal-to-noise ratio of the measurement.

[0053] Furthermore, in a scalable quantum processor architecture based on superconducting qubits, it is important to minimize the number of input and output lines entering a mixing cryostat. One way to achieve this on the output side is, for example, to combine multiple readout signals from multiple qubits on the same output line using hybrids or commercial power combiners. Subsequently, a quantum-limited broadband amplifier can be used to amplify the multiple readout signals before they propagate through the output chain. However, using such hybrids or power combiners attenuates the quantum signals before the amplifier, resulting in a significant loss of quantum information and thus limiting the efficiency of quantum measurement.

[0054] Another possibility is to add the power combiners after the multiple quantum-limited amplifiers that amplify each individual signal. However, the disadvantage of this scheme is the addition of extensive hardware (multiple amplifiers) to the mixing cryostat, which limits the scalability of such a scheme. A solution chiller is a cryogenic unit that enables continuous cooling to low temperatures of approximately 7 mK without any moving parts in the low-temperature range.

[0055] The following are some examples of power combiners or dividers.

[0056] The following are characteristics of a power combiner with a T-junction: 1) 3-terminal unit with one input terminal and two output terminals, 2) lossless, 3) reciprocal, 4) no separation between the output terminals, and 5) merely adapted to the input.

[0057] Characteristics of a resistor divider include the following: 1) 3-terminal unit, 2) reciprocal, 3) can be matched to all terminals (no reflection), 4) lossy, and 5) no separation between the output terminals.

[0058] The characteristics of hybrids (90° and 180° hybrids) include the following: 1) 4-terminal units with two input terminals and two output terminals, 2) reciprocal, 3) can be adapted to all terminals (no reflection), 4) good separation between the two input terminals and between the two output terminals. When the hybrids are used as power combiners, the power is divided equally between the two output terminals, resulting in a loss of half the information.

[0059] The following are characteristics of a Wilkinson power divider / combiner: 1) 3-terminal unit with one input and two output terminals (can be generalized to an N-way unit), 2) matched at all terminals (no reflection), 3) isolation between the two output terminals, 4) lossy when combining signals input at the output terminals, as only half of the signal power appears at the input, while the other half is lost.

[0060] One or more embodiments address problems or issues related to multiplexing the driving and readout of multi-qubit resonator systems using a small number of input and output lines (thus providing scalability), without causing any loss of quantum information (lossless) and without allowing signal leakage between different qubit resonator systems (separation between input terminals and / or separation between output terminals). These embodiments include one or more methods and units that separate the microwave signals (drive signals and readout signals) based on their frequency, enabling the methods and units to multiplex the readout and driving of multiple qubits without attenuating the microwave signals used in the drive / readout process. Furthermore, the units are equipped with isolation between the different terminals.

[0061] According to one or more embodiments, the unit can be a superconducting on-chip microwave combiner and / or distributor with multiple connections for the quantum signals. The microwave combiner and distributor are lossless, and their connections are adapted to the input / output environment. The superconducting microwave combiner and / or distributor can be used in scalable quantum processing architectures, such as for qubit addressing and readout.

[0062] In one or more embodiments, a microwave combiner and splitter are configured in the same unit. The direction of the input signals determines whether the unit operates as a microwave combiner or splitter.

[0063] Fig. Figure 10 is a schematic representation of a unit that constitutes a microwave combiner for quantum signals according to one or more embodiments. The unit 1000 It is configured to use frequency multiplexing to allocate different frequencies for different microwave signals on a single output transmission line.

[0064] The unit 1000 contains bandpass microwave filters, commonly known as bandpass filters 105 The various bandpass filters 105 are represented as bandpass filters 105_1 to 105_N. Each bandpass filter 105It has a differently narrow passband through which microwave signals with a frequency within that specific narrow passband are transmitted (i.e., passed through), and signals with a frequency outside that specific narrow passband are reflected (i.e., blocked). The bandpass filter 105_1 has its own narrow passband with a bandwidth 1 (BW1), the bandpass filter 105_2 has its own narrow passband with a bandwidth 2 (BW2) and the bandpass filter 105_N has its own narrow passband with a bandwidth N (BW N ).

[0065] For example, the bandpass filter 105_1 is configured with a passband (frequency band) that allows a microwave signal 305_1 with frequency f1 to pass through (transmit), but all other microwave signals 305_2 to 305_N with frequencies f2 to f NSignals that lie outside the passband for bandpass filter 105_1 are blocked (reflected). Similarly, bandpass filter 105_2 is configured with a passband (frequency band) that allows a microwave signal 305_2 with frequency f2 to pass through (transmit), but all other microwave signals 305_1, 305_3 to 305_N with frequencies f1, f3 to f N Signals that lie outside the passband for the bandpass filter 105_2 are blocked (reflected). Similarly, the bandpass filter 105_N is configured with a passband (frequency band) that allows a microwave signal 305_N with frequency f to pass through. N is passed through (transmitted), but all other microwave signals 305_1 to 305_N-1 with frequencies f1 to f N-1Signals that lie outside the passband for the bandpass filter 105_N are blocked (reflected). The microwave signals 305_1 to 305_N are generally referred to as microwave signals. 305 denoted. When cavity-qubit quantum systems with the unit 1000 If they are functionally connected, the microwave signals can 305 at the respective frequencies f1 to f N are intended to be used to control specific qubits, or for reading out qubits (via readout resonators or cavities), as understood by a person skilled in the art.

[0066] For example, a bandpass filter can 105 can have a passband of 1 megahertz (MHz), another bandpass filter 105 It can have a passband of 10 MHz, and yet another bandpass filter. 105 It can have a passband of 100 MHz, etc.

[0067] The unit 1000 includes connectors 10, each individually with its respective bandpass filter 105 are connected. In particular, the various connections are 10 as a connection 1 , Connection 2 up to terminal N, where terminal N is the last of the terminals 10 represents. Similarly, N represents the last of the frequencies of the microwave signals. 305 , the bandpass filter 105 of quantum systems 3050 (in Fig. (Explained below, section 12) and so on. In the unit 1000 is the connection 1 connected to the bandpass filter 105_1, the connection 2 Terminal 1 is connected to bandpass filter 105_2, and terminal 1 is connected to bandpass filter 105_N. Each terminal 1 through terminal 1 is connected to one end of its own bandpass filter 105_1 via a bandpass filter 105_N. The other end of bandpass filter 105_1 is connected to bandpass filter 105_N via a common node.115 with a common connection 120 connected. The common node 115 A common connection point, a common transmission line, a common line, etc., can be a reciprocal point for electrical connection. The common connection 120 is connected to each bandpass filter 105_1 via the bandpass filter 105_N, while the individual connections 10 (connections) 1 to N) are connected (only) to their respective bandpass filter 105_1 by a bandpass filter 105_N.

[0068] Since the bandpass filters 105_1 to 105_N only transmit corresponding microwave signals 305_1 to 305_N in their respective passbands, the unit 1000 configured so that each bandpass filter 105_1 covers a different frequency band (or sub-band) of frequencies through the bandpass filter 105_N, so that no passband (the bandpass filter) 105) overlaps. Accordingly, all connections are 1 , 2 up to N are isolated from each other, as they are connected to their respective bandpass filters 105_1 to 105_N, so that no microwave signal 305 (entering or exiting) through any connection 10 via the common node 115 into another connection 10 It leaks. Therefore, every connection 10 from other connections 10 isolated and designed to transmit its own microwave signal 305 transmits at a predefined frequency (or within a predefined frequency band) as a result of using its own bandpass filter 105 is connected. Therefore, the bandpass filters 105_1 to 105_N are responsible for the isolation between the connections. 10 (e.g. connection) 1 , Connection 2 to provide up to connection N).

[0069] The respective connections10 , the bandpass filters 105 , the common node 115 and the common connection 120 are connected via transmission lines 30 connected. At the transmission line 30 It could be a stripline, microstripline, etc. The microwave bandpass filters 105 These filters are designed and implemented using lossless or low-loss lumped elements such as superconducting coils, superconducting gap capacitors and / or plate capacitors, and passive superconducting elements. The superconducting elements include lumped element coils, gap capacitors, and / or plate capacitors (with low-loss dielectrics). Other possible implementations of the bandpass filters include coupled line filters and / or capacitively coupled series resonators.

[0070] The respective connections 10 , bandpass filter 105, the common node 115 , the common connection 120 and the transmission lines 30 They are made of superconducting materials. Examples of superconducting materials (at low temperatures, for example, 10 to 100 mK or about 4 K) include niobium, aluminum, tantalum, etc.

[0071] In one version of the unit 1000 As a microwave combiner, a coaxial cable can be connected to the outer ends of the 10 and 120 connections, so that coaxial cables with connections 10 are connected, at which microwave signals are transmitted through 305_1 to 305_N at different frequencies f1 to f N be entered, while another coaxial cable, connected to the common port, 120 The connected device outputs the combined microwave signals 305_1 to 305_N. In the microwave combiner, all microwave signals 305_1 to 305_N are extracted at their respective frequencies f1 to f1. Nnone of the microwave signals 305 via one of the other (input) connections 10 instead of being returned (i.e., disconnection), each microwave signal 305_1 to 305_N passes through its respective bandpass filter 105_1 to 105_N, passes through the common node, and exits via the common terminal. 120 Therefore, the microwave combiner combines the microwave signals 305_1 to 305_N and outputs them via the common connection. 120 out. The unit 1000 is with the frequency relationship f1 < f2 <... < f N configured, with each frequency being f1, f2, ... f N This concerns the center frequency of the bandpass filters 105_1 to 105_N. The unit 1000 is configured to satisfy the following inequality B W j + B W i 2 < | f j − f i | where i,j = 1, 2, ... N and j ≠ i. This inequality requires that the frequency spacing between the center frequencies of each pair of bandpass filters exceeds their average bandwidths. In other words, the inequality ensures that no bandpass filters have overlapping bandwidths (i.e., frequency ranges).

[0072] Every connection 1 up to connection N with its corresponding transmission line 30 (and the respective bandpass filter 105_1 to 105_N) is considered a different / separate channel / input, and at the common connection 120 This is a shared channel. Accordingly, when operating as a power combiner, multiple input channels of the connections are required. 1 up to N with the (only) common channel of the common connection 120 connected. The unit 1000It is configured to be bidirectional. As mentioned here, the same unit can 1000 It can be used both as a microwave power combiner and as a microwave signal distributor.

[0073] Fig. Figure 11 is a schematic representation of the unit 1000 , which represents a microwave distributor for quantum signals according to one or more embodiments. The microwave distributor unit 1000 is configured so that it connects to the common port 120 The microwave signals 305_1 to 305_N were sent to the individual terminals. 1 up to N, in which the microwave signals 305_1 to 305_N are directed / distributed according to the passband of the respective bandpass filter 105_1 to 105_N.

[0074] In one version of the unit 1000 As a microwave distributor, a coaxial cable can be used with the outer ends of the common connection. 120be connected in such a way that the coaxial cable is connected to the common terminal 120 is connected, to which the microwave signals 305_1 to 305_N at different frequencies f1 to f N are entered, while others are connected to the output ports. 10 The connected coaxial cables output the individual microwave signals 305_1 to 305_N. In the microwave distributor, for each microwave signal 305_1 to 305_N, a certain number of connections are permitted at its respective frequency f1 to f1. N only individual frequencies f1 to f N the respective bandpass filters 105_1 to 105_N pass through, which have a passband that covers the corresponding frequency f1 to f N covers, and thus the individual connection 1 to terminal N. Since each of the bandpass filters 105_1 to 105_N has no overlapping passband, the microwave signal 305_1 to 305_N has its own frequency f1 to f N, which is predefined to pass only one of the bandpass filters 105_1 to 105_N. The microwave signals 305 at one of their own frequencies f1 to f N through the joint connection 120 input, and each microwave signal from 305_1 to 305_N passes through the common node. 115 , is transmitted through its respective bandpass filter 105_1 to 105_N and passes through the individual connections 1 up to N according to the frequency f1 to f N off. Every connection 1 up to N gives (only) its own respective frequency f1 to f N due to the filtering by the respective bandpass filters 105_1 to 105_N. In other words, the connection 1 The microwave signal 305_1 is output at frequency f1 (via the bandpass filter 105_1), while the bandpass filter 105_1 filters out frequencies f2 to f N blocks. The connection 2The microwave signal 305_2 is output at frequency f2 (via the bandpass filter 105_2), while the bandpass filter 105_2 filters out frequencies f1, f3 to f N It blocks. Similarly, terminal N outputs the microwave signal 305_N with the frequency f. N (via the bandpass filter 105_N) while the bandpass filter 105_N filters the frequencies f1 to f N-1 locks.

[0075] In Fig. 11 will be each connection 1 up to connection N with its respective transmission line 30 (and the respective bandpass filter 105_1 to 105_N) are considered as different / separate channels / outputs, and at the common connection 120 This involves a shared channel / input. Accordingly, when operating as a power distributor, multiple output channels are required for the connections. 1 up to N with the (single) common (input) channel of the common connection 120 tied together.

[0076] As in the Fig. 10 and Fig. The unit can be identified as 11. 1000 configured so that it can be operated both as a microwave signal distributor and as a combiner, depending on whether the connections 10 or 120 the input of microwave signals 305 received.

[0077] Fig. 12 is a system 300 , which is the unit used in a quantum system application according to one or more embodiments 1000 represents. Fig. 12 is an exemplary application of the unit 1000 , which represents a frequency-division multiplexed readout of qubits, where the microwave signals 305_1 to 305_N have frequencies f1 to f N are present, which correspond to the respective resonant frequencies of the cavities / resonators 1up to N match or nearly match. It should be noted that the example can be applied equally to drive the qubit by using microwave signals 305_1 to 305_N with frequencies f1 to f2 instead. N are present, which correspond to the respective resonant frequencies of the qubits 1 up to N match or nearly match.

[0078] In the system 300 are quantum systems through 3050_1 to 3050_N, each with the (input) connection 1 connected up to terminal N. Quantum systems can generally be referred to as quantum systems. 3050 These can be described. In the quantum system 3050_1, this can be a cavity and a qubit. 1 These are functionally interconnected elements. In the quantum system 3050_2, this could be a cavity and a qubit. 2These are functionally connected elements. Similarly, the quantum system 3050_N can be a cavity and a qubit N that are functionally connected. In the quantum system 3050 The cavity and the qubit can be capacitively connected, connected within a two-dimensional cavity, and / or connected within a three-dimensional cavity, as is clear to a person skilled in the art. One type of qubit is a superconducting qubit containing at least one Josephson junction, where a Josephson junction is a nonlinear, non-dissipative coil formed from two superconducting metals (e.g., aluminum, niobium, etc.) sandwiching a thin insulator, such as aluminum oxide, niobium oxide, etc.

[0079] In an implementation, the system can 300 also a broadband quantum-limited amplifier 350included, which is connected to the common connection 120 (whose output) is connected. The broadband quantum-limited amplifier 350 It has a wide bandwidth designed to accommodate all microwave signals. 305 to be amplified, the respective frequencies f1 to f N have.

[0080] Every quantum system 3050 is designed to oscillate at its own resonant frequency, which is unique to each quantum system 3050 It is different. An expert recognizes that the void in every quantum system is different. 3050is a resonator, or is operated as such, so that the cavity oscillates at its own resonant frequency, which is usually called the readout resonator frequency. In particular, the cavity in quantum system 3050_1 is configured to resonate, for example, at its resonant frequency, which is the frequency f1. The cavity in quantum system 3050_2 is configured to resonate, for example, at its resonant frequency, which is the frequency f1. Similarly, the cavity in quantum system 3050_N is configured to resonate at its resonant frequency, which is the frequency f1. N is, is in resonance.

[0081] The quantum systems 3050 are with the unit 1000 via capacitors 325 connected, and the quantum systems 3050 are via capacitors 320connected to the external environment. The external environment may include equipment for generating microwave signals.

[0082] During the frequency-multiplexed readout of the respective qubit in the quantum system 3050_1 in the system 300 The microwave signal 305_1 has the frequency f1, the resonant frequency for the cavity in the quantum system 3050_1, and the microwave signal 305_1 has the frequency f1 to connect both the 1 as well as defining the bandpass filter 105_1 as the target (since the bandpass filter 105_1 is designed to pass frequency f1). During the frequency-division multiplexed readout of the respective qubit in the quantum system 3050_2, the microwave signal 305_2 has frequency f2, the resonant frequency for the cavity in the quantum system 3050_2, and the microwave signal 305_2 has frequency f2 to both connect 2as well as defining the bandpass filter 105_2 as the target (since the bandpass filter 105_2 passes the frequency f2). During the frequency-division multiplexed readout of the respective qubit in the quantum system 3050_N, the microwave signal 305_N has the frequency f N , the resonance frequency for the cavity in the quantum system 3050_N, and the microwave signal 305_N has the frequency f N , in order to define both the N terminal and the 105_N bandpass filter as the target (since the 105_N bandpass filter is designed to filter the frequency f N (passes through). The microwave signals 305_1 to 305_N with the respective resonant frequencies f1 to f N cause the quantum systems 3050_1 to 3050_N to each resonate, and therefore the microwave signals cause 305(at the respective resonant frequencies) the reading out of the respective qubits, which are connected to their respective cavity (resonator). Thus, the microwave signal 305_1, after interaction with the quantum system 3050_1 (i.e., the qubit resonator), is transmitted via the connection 1 to the bandpass filter 105_1, via the common connection 120 and to the broadband quantum-limited amplifier 350 The microwave signal 305_2 is transmitted after interaction with the quantum system 3050_2 (i.e., the qubit resonator) via the connection 2 to the bandpass filter 105_2, via the common connection 120 and to the broadband quantum-limited amplifier 350 Similarly, the microwave signal 305_N, after interacting with the quantum system 3050_N (i.e., the qubit resonator), is transmitted via terminal N to the bandpass filter 105_N, via the common terminal. 120 and to the broadband quantum-limited amplifier350 transmitted. After interacting with the respective quantum system 3050_1 to 3050_N, each of the microwave signals 305_1 to 305_N contains quantum information (e.g., the state) of the respective qubits. All microwave signals 305_1 to 305_N are (simultaneously) amplified by the broadband quantum-limited amplifier. 350 reinforced.

[0083] The quantum signal is a microwave signal. It is understood that the microwave signal 305 in the unit 1000 It can be transmitted bidirectionally.

[0084] Fig. 13 illustrates units 1000 as a cascade-like tree structure of power combiners according to one or more embodiments. Fig. 13 is an example of scaling the units 1000 The building elements 1000 are configured so that they can be manufactured on a wafer, for example as a chip. To be in Fig. 13. To avoid distracting from the essentials, some details of the units are 1000 For the sake of clarity, these details have been omitted. It is understood that these details are included in an analogous manner, as explained herein.

[0085] This example shows the tree structure of power combiners with two levels. Other implementations may have three, four, five... ten or more levels in the power combiner tree structure. Fig. 13 can form M groups of units 1000 in the plain 2 are located, and the M groups of units 1000 Each has N inputs in the plane 2 The presence of N inputs means that each unit 1000 in the plain 2 the corresponding number of N connections 10 has each with its corresponding bandpass filter 105 are connected. As explained here, each of the N inputs has a single connection. 10and a single bandpass filter 105 on a one-to-one basis. On the plane 2 have the units 1000 Bandpass filter 105 , where each of the bandpass filters 105 , as explained here, it has a different passband (i.e., a different frequency band), so there is no overlap in frequency coverage.

[0086] Each of the power combiner units 1000_1 to 1000_M is configured to transmit microwave signals on its respective medium transmission line 30_1 through 30_M. 305 outputs. The designation of the transmission line 30_1 to 30_M is used to show that each of the power combiner units 1000_1 to 1000_M has its own output transmission line. 30 has, and accordingly the total number of medium transmission lines is 30 from the units 1000 in the plain 2 equal to M. In the plane 1The unit 1000_Z has a number of M inputs. The output of each unit 1000_1 to 1000_M is individually connected to its own input from the number of M inputs of the unit 1000_Z, so that each of the center transmission lines 30_1 to 30_M is one input from the M inputs of the unit 1000_Z.

[0087] The unit 1000_Z is associated with the units 1000 identical to those explained here.

[0088] However, the 1000_Z unit is designed such that each of the M inputs is in the plane 1 its own connected bandpass filter 105 with a passband that includes all passbands of the bandpass filters 105 on the lower level 2 per center transmission line 30 covers. In the plain 1 the tree structure 400 For example, the unit 1000_Z has a first input (of the M inputs) with the connection 1 , so that their bandpass filter 105in the plain 1 all passbands of the bandpass filters in the unit 1000_1 in the plane 2 contains. Similarly, the unit 1000_Z in the plane 1 the tree structure 400 a second input (of the M inputs) with the connection 2 , so that their bandpass filter 105 in the plain 1 all passbands of the bandpass filters in the unit 1000_2 (not shown) in the plane 2 It contains. Up to the last input (of the M inputs) in the plane. 1 the tree structure 400 The unit 1000_Z has a final input with the terminal N, so that its bandpass filter 105 in level 1 all passbands of the bandpass filters in the unit 1000_M in plane 2 contains.

[0089] On the plain 1Unit 1000_Z is configured to receive microwave signals 305_1 to 305_Z at the M inputs and to combine these signals so that they are output on the medium transmission line 30_Z. The tree structure is configured accordingly. 400 Power units are enlarged (scaled) in such a way that the unit 1000_Z of the plane 1 M x N microwave signals 305 outputs the M groups of units 1000 in the plain 2 correspond, with each of the units 1000 The level has 2 N inputs. The direction of the microwave signals 305_1 to 305_Z is shown in the tree structure. 400 , which is operated as an enlarged (scaled) power combiner. Similarly, the direction of the microwave signals 305_1 to 305_Z can be switched so that it can be operated as an enlarged (scaled) signal distributor.

[0090] Fig. Figure 14 is a schematic representation of the unit. 1000 , which represents a microwave combiner for quantum signals according to one or more embodiments. The unit 1000 It contains all of the numerous features explained here. Furthermore, the unit contains 1000 additional features to ensure impedance matching for the transmitted microwave signals (i.e., to minimize reflections along the signal path) and also the connection of multiple branches / lines to the common node 115 to enable.

[0091] In Fig. 14 are impedance converters 505_1 to 505_N, each located between the respective terminals. 1 up to N and their associated bandpass filters 105_1 to 105_N added. The unit 1000 It also includes a broadband impedance converter. 510 , which is connected to the common node 115 and the joint connection 120is connected. The impedance converters 505_1 to 505_N and the impedance converter 510 are configured to provide impedance matching. At one end of the unit 1000 The impedance converters 505_1 to 505_N are designed such that they are compatible with the input impedance Z0 of the terminals 1 up to N match (or nearly match) and are matched to the associated bandpass filter 105_1 to 105_N. Each of the impedance converters 505_1 to 505_N is configured to have a characteristic impedance Z = Z 0 Z H has, where Z0 is the input impedance (as well as the output impedance), Z H The high impedance of the bandpass filters is 105_1 to 105_N, and Z is the average impedance of each impedance converter, 505_1 to 505_N. The average characteristic impedance Z is the square root of the product of Z0 and Z. HOne reason why converting the impedance Z0 of the unit's terminals into a high characteristic impedance Z H One advantage that can be useful in the area of ​​the common node is that, in general, high-impedance transmission lines, such as microstrips or striplines, have narrow conductor tracks. This minimizes the physical size of the common node and allows a larger number of lines to be joined at that node. This is particularly relevant when the bandpass filters are implemented as coupled line filters and / or capacitively coupled resonators. However, if all filters are implemented with lumped elements (with very small footprints), such impedance conversions are less problematic.

[0092] In one implementation, the impedance converters 505_1 to 505_N can be impedance-matching transmission lines, where at one end (for example, the left end) a broadband matching of the input impedance Z0 is performed and at the opposite end (for example, the right end) a narrowband matching of the high impedance Z is performed. H the bandpass filter 105 This is done. Each of the impedance matching converters 505_1 to 505_N has a length corresponding to its own respective relationship. λ 1 4 , λ 2 4 , … , λ N 4 , where λ1 is the wavelength of the microwave signal 305_1, where λ2 is the wavelength of the microwave signal 305_2, up to λ N , where this is the wavelength of the microwave signal 305_N. These impedance converters generally have narrow bandwidths.

[0093] In one implementation, the broadband impedance converter can be 510This involves an impedance-matching transmission line, in which a narrowband matching of the high impedance Z is used at one end (for example, the left end). H the bandpass filter 105 (via the common node) 115 ) while at the opposite end (e.g., the right end) a broadband impedance matching to the output impedance Z0 takes place. Such a broadband impedance converter 510This can be implemented using tapered transmission lines, for example, transmission lines whose widths change adiabatically depending on the maximum signal wavelength. Other implementations of tapered lines known to those skilled in the art are also possible, such as exponential taper or Klopfenstein taper. It should also be noted that the broadband requirement for this impedance converter differs from that of other converters. 505 This results from the fact that this broadband converter must be matched to the characteristic impedance for a wide range of signal frequencies transmitted by it, unlike impedance converters. 505 , where the impedance only needs to be adjusted for a narrow frequency range centered around the corresponding center frequency of the bandpass.

[0094] The impedance converters 505_1 to 505_N and the impedance converter 510 are, as explained here, made from superconducting materials such as niobium, aluminum, tantalum, etc.

[0095] The impedance designation Z0 refers to the characteristic impedance at the terminals. 10 and 120 (which can be the input and output ports, or vice versa). For example, each port can be used 10 and 120 the characteristic impedance Z0 is 50 ohms (Ω), as can be seen by those skilled in the art.

[0096] A method for configuring a superconducting microwave combiner unit 1000 is provided according to one or more embodiments. It can be applied to the Fig. 10 to Fig. Reference is made to section 14. A first filter 105_1 up to a last filter are provided. The first filter 105_1 up to the last filter 105_N are each connected to a first input up to a last input (e.g., a transmission line). 30 , each individually connected to the respective ports 10 (connected). The first filter 105_1 to the last filter 105_N each have a first passband up to a last passband (each for the frequencies f1 to f N ), so that the first passband to the last passband are each different. A common output (e.g., one with the common connection) 120 connected transmission line 30The first input is connected to the last input via the first filter 105_1 and then to the last filter 105_1. The first input and the last input are isolated from each other, thus preventing signal loss between them. The first filter and the last filter are each configured to carry signals (e.g., microwave signals 305_1 to 305_N) with different sets of frequencies. The first filter and the last filter (e.g., the bandpass filters 105_1 to 105_N) are all passive, meaning no power is required for operation as passive filters and no power amplification is necessary.

[0097] The first filter 105_1, running from the first filter to the last filter, is configured to pass only signals at a first set of frequencies. The next filter 105_2, running from the first filter to the last filter, is configured to pass only signals at a second set of frequencies. Finally, the last filter 105_N, running from the first filter to the last filter, is configured to pass only signals at a final set of frequencies. The first, next, and last sets of frequencies do not overlap (i.e., their passbands do not overlap).

[0098] From the first input to the last input, each contains a first connection (e.g., connection). 1 ) or a final connection (e.g., connection N). The first connection 1The connections up to the last terminal N are functionally connected to the first filter 105_1 up to the last filter 105_N, so that the first to last signals (e.g. microwave signals 305_1 to 305_N or microwave signals 305_1 to 305_Z) are Fig. 13), which are each entered through the first connection to the last connection, are linked together and via a common connection 120 to be output. A first impedance converter 505_1 up to a last impedance converter 505_N are each connected between the first terminal 1 or the last connection N and first filter 105_1 or last filter 105_N are connected. The first impedance converter up to the last impedance converter are each configured to provide impedance matching, as shown in Fig. 14 explained. A common impedance converter 510 is between the first filter 105_1 and the last filter 105_N and the common connection 120switched, and the common impedance converter 510 It is configured to provide impedance matching. The first filter up to the last filter are each superconducting, and the first filter up to the last filter each contain superconducting materials.

[0099] A method for configuring a superconducting microwave distribution unit is described. 1000 provided according to one or more embodiments. It can be applied to the Fig. 11 to Fig. Reference is made to paragraph 14. The superconducting microwave distributor and the superconducting microwave combiner are the same unit. However, the microwave distributor and the combiner are operated in opposite directions, as described. In particular, the input and output terminals are configured with respect to the microwave signals input and output. 305They are used in reverse order. A first filter up to a last filter are provided. The first filter 105_1 up to the last filter 105_N are each connected to a first output up to a last output (e.g., a transmission line). 30 , each with its respective connection 10 (connected). The first filter 105_1 to the last filter 105_N each have a first passband up to a last passband (for corresponding frequencies f1 to f). N ), so that the first passage area is different from the last passage area. A common entrance (e.g., the one with the common connection) 120 connected transmission line 30 ) is connected from the first output to the last output via the first filter 105_1 to the last filter 105_N.

[0100] The first output through the last output are each isolated from each other, thus preventing signal loss between them. The first filter through the last is configured to carry signals (e.g., microwave signals 305_1 to 305_N) with different sets of frequencies. The first filter through the last (e.g., bandpass filters 105_1 to 105_N) are each passive, meaning no operating power is required to operate as passive filters and no power gain is generated.The first filter 105_1, from the first filter to the last filter, is configured to pass only signals at a first set of frequencies. The next filter 105_2, from the first filter to the last filter, is configured to pass only signals at a next set of frequencies. Finally, the last filter 105_N, from the first filter to the last filter, is configured to pass only signals at a last set of frequencies. The first, next, and last sets of frequencies do not overlap (i.e., the passbands do not overlap). The first output to the last output each contain a first terminal (e.g., terminal ). 1 ) to a final connection (e.g., connection N). The first connection 1Up to the last connection N, each is functionally connected to the first filter 105_1 up to the last filter 105_N, so that a first to a last signal (e.g. microwave signals 305_1 to 305_N or microwave signals 305_1 to 305_Z in Fig. 13) are output via the first connection to the last connection. The first to last signals (e.g., microwave signals 305_1 to 305_N or microwave signals 305_1 to 305_Z in Fig. 13) are connected together at different frequencies via a common connection 120 Entered. A first impedance converter 505_1 up to a last impedance converter 505_N are each connected between the first terminal. 1 up to the last connection N and the first filter 105_1 up to the last filter 105_N. The first impedance converter up to the last impedance converter are each configured to provide impedance matching as shown in Fig. 14 explained. A common impedance converter 510 is between the first filter 105_1 and the last filter 105_N and the common connection 120 switched, and the common impedance converter 510 It is configured to provide broadband impedance matching. The first filter up to the last filter are each superconducting, and the first filter up to the last filter each contain superconducting materials.

[0101] One or more embodiments contain a superconducting system 300 The first filter 105_1 and the last filter 105_N are configured to be connected to the first quantum system 3050_1 and the last quantum system 3050_N, respectively. Each filter has a first passband and a last passband (representing frequencies f1 to f1). N(included), so that the first passage area is different from the last passage area. A common output (e.g., the one with the common connection) 120 connected transmission line 30 ) is connected with the first quantum system 3050_1 to the last quantum system 3050_N via the first filter 105_1 to the last filter 105_N.

[0102] The first quantum system 3050_1 up to the last quantum system 3050_N are each configured such that they resonate at a first frequency (for example, the frequency f1) up to a last resonance frequency (f N) oscillate. The first filter up to the last filter are configured to operate in transmission mode (passing / transmitting the signal) from the first resonant frequency to the last resonant frequency, so that each filter from the first to the last filter receives (only) one frequency from the first resonant frequency f1 to the last resonant frequency f1. N is assigned. The first filter up to the last filter are each configured to operate in reflection mode (i.e., block) for all other resonant frequencies from the first resonant frequency to the last resonant frequency, with the exception of the resonant frequency associated with that frequency. In other words, the frequencies f1 to f Nare chosen so that they coincide with / overlap the own resonant frequency of the quantum systems 3050_1 to 3050_N on a one-to-one basis.

[0103] Technical effects and advantages include techniques and units that separate microwave signals based on their frequency, enabling the unit to multiplex the readout and drive of multiple qubits without attenuating the microwave signals used for driveout and / or readout. Further technical advantages include the separation between the various connections in a power combiner and signal distributor.

[0104] Using the units explained here 100 and 1000In one or more embodiments, methods and systems are provided to minimize the number of input and output lines required for initializing, computing (or manipulating) and reading out a large number of superconducting qubits.

[0105] In many experiments with superconducting qubits, current state-of-the-art methods require at least two microwave lines per qubit in a cooling solution for initialization, computation (or manipulation), and measurement of these qubits (i.e., with their input and output lines). However, due to the limited space and cooling capacity of the cooling solution, such a line allocation is not scalable to large quantum processors with more than 50 qubits.

[0106] However, according to one or more embodiments, in one implementation the input and output techniques are scalable to more than 500 qubits with a minimal number of input and output lines.

[0107] The Fig. 15, Fig. 16, Fig. 17 and Fig. Figure 18 illustrates various systems for controlling and reading qubits according to one or more embodiments. Fig. 15 is a system 1500 for qubit addressing and qubit readout according to one or more embodiments. The system 1500 This illustrates operation in reflection mode, where the same input and output lines (I / O lines) (i.e., transmission lines) are used for reading the qubits and for the qubit pulses.

[0108] The system 1500 contains an array of resonator-qubit systems 1520There are individual qubits 1550_1 to 1550_N (generally referred to as qubits). 1550 (designated) and selection resonators 1555_1 to 1555_N (selection resonators 1555 ). In the arrangement of the resonator-qubit systems 1520 Does a qubit have a one-to-one relationship? 1550 to its own selection resonator 1555 , so that the state of the specific qubit 1550 by reading its readout resonator 1555 can be read / derived. Accordingly, the arrangement of resonator-qubit systems contains 1520 An arrangement of individually addressable qubits 1550_1 to 1550_N, which are connected to their respective (individually addressable) readout resonators 1555_1 to 1555_N, as is known to a person skilled in the art. Each readout resonator 1555 in the arrangement of resonator-qubit systems 1520is designed to oscillate at its own readout resonant frequency, which is predefined differently for each readout resonator 1555_1 to 1555_N. Similarly, each individual qubit 1550_1 to 1550_N can be designed to have its own qubit frequency (for driving the qubit), which is predefined so that in one implementation it is different for each qubit 1550_1 to 1550_N. In another implementation, the qubit frequencies need not be different, and some may be different while some may be the same. A person skilled in the art recognizes that a cavity can act as a readout resonator such that the cavity oscillates at its own readout resonant frequency. For example, in the resonator-qubit systems 1520 about an arrangement of cavity qubit systems 3050_1 to 3050_N, which are in Fig. 12 will be explained.

[0109] The arrangement of resonator qubit systems 1520 is equipped with a superconducting microwave switch / router 100 connected, which is designated 100_1, since in Fig. Figure 15 illustrates more than a superconducting microwave switch / router. The superconducting microwave switch / router 100_1 is a 1-N quantum switch / router that uses an array of resonator qubit systems. 1520 is connected. As explained here, the superconducting microwave switch / router 100_1 is bidirectional. The superconducting microwave switch / router 100_1 is configured with terminals that correspond to the terminals of the resonator qubit system array. 1520 via transmission lines 30 are connected. Each connection of the arrangement of resonator-qubit systems 1520Each resonator qubit is individually addressable and / or connected to a single resonator qubit system, allowing data exchange with each individual resonator qubit system. For example, one resonator qubit system is qubit 1550_1, which is connected to its readout resonator 1555_1. Another resonator qubit system is qubit 1550_2, which is connected to its readout resonator 1555_2, up to the last resonator qubit system containing qubit 1550_N, which is connected to its readout resonator 1555_N.

[0110] In this example, the superconducting microwave switch / router 100_1 has a suitable number of terminals that correspond to terminals of the resonator qubit system arrangement. 1520 are connected, and N terminals of the superconducting microwave switch / router 100_1 are connected to N terminals of the resonator qubit system array. 1520connected via transmission lines 30_1 to 30_N. The first connection of the superconducting microwave switch / router 100_1 and the arrangement of resonator qubit systems. 1520 are connected via the transmission line 30_1, while the last connection of the superconducting microwave switch / router 100_1 and the arrangement of resonator qubit systems 1520 are connected via transmission line 30_N.

[0111] The system 1500 includes a low-loss broadband circulator 1505 , which is connected at one end to a single terminal of the superconducting 1-N microwave switch / router 100_1. The superconducting microwave switch / router 100_1 has one terminal at one end and N terminals at the other end, with each end capable of acting as an input or output. The single terminal is configured to carry a signal through associated tunable filters. 20to the 1 to N terminals, as shown here in the Fig. 1 to Fig. 9 explained. Each of the N terminals of the superconducting 1-N microwave switch / router 100_1 has a tunable filter. 20 with a total of N tunable filters 20 Assigned, i.e., one filter per transmission line 30_1 to 30_N. The low-loss broadband circulator 1505 is connected to one terminal of the superconducting microwave switch / router 100_1, while the terminals 1 up to N of the superconducting microwave switch / router 100_1 are connected to the other end of the resonator-qubit system array. The low-loss broadband circulator 1505 It can be made of superconducting materials. The low-loss broadband circulator 1505 It is broadband because it is designed in such a way that it can utilize the frequency range in each of the tunable filters. 20 covered frequencies in the connections 1up to N of the superconducting microwave switch / router 100_1 covers / conducts.

[0112] In Fig. The system contains 15 1500 another superconducting microwave switch / router 100 , which is referred to as the superconducting 1-2 microwave switch / router 100_2 (quantum switch), because the superconducting microwave switch / router 100_2 has a connection that has 2 tunable filters 20 as discussed here, it is connected / can be connected to two other connections. The low-loss broadband circulator 1505 is connected to one terminal of the superconducting microwave switch / router 100_2, while the other two terminals of the superconducting microwave switch / router 100_2 are individually connected to a cold load / dump 1510 and a quantum-limited broadband directional amplifier 350 are connected. The quantum-limited broadband directional amplifier 350amplifies the reflected readout signal, which carries the quantum information of the respective qubit in the arrangement of the resonator-qubit systems. 1520 includes. During a cold load / dump 1510 This can be a 50-ohm (Ω) environment in which the outgoing qubit drivers / pulses are applied, and the qubit pulses are the qubit driver pulses used to drive the desired qubit in the resonator-qubit system array. The superconducting microwave switches / routers 100_1 and 100_2 represent two separate superconducting microwave switches / routers in the system. 1500 , and their details can be found in the in the Fig. 1 to Fig. 14 explained superconducting microwave switches / routers 100 can be found.

[0113] Now, an example of qubit pulses for controlling the qubits will be explained, in which the qubits are controlled with time-division multiplexed microwave signals, such as the microwave signals explained above. 305 The arrangement of resonator-qubit systems 1520 The system contains one qubit 1550_1 up to one qubit 1550_N, each individually connected to its own readout resonator 1555_1 to 1555_N, with qubit 1550_1 being connected to its readout resonator 1555_1 (e.g., capacitively or inductively), qubit 1550_2 being connected to its readout resonator 1555_2, up to one qubit 1550_N being connected to its readout resonator 1555_N. The transmission line 30_1 is connected to qubit 1550_1 and readout resonator 1555_1 in the arrangement of resonator-qubit systems. 1520 The transmission line 30_2 is connected to the qubit 1550_2 and the readout resonator 1555_2 in the arrangement of resonator-qubit systems. 1520Similarly, the transmission line 30_N is connected to the qubit 1550_N and the readout resonator 1555_N in the arrangement of resonator-qubit systems. 1520 tied together.

[0114] In an implementation where each qubit 1550_1 to 1550_N can have its own qubit frequency (i.e., each qubit frequency is different), each qubit 1550_1 to 1550_N can be individually addressed. In another implementation, some of the qubit frequencies may be the same, and others may not, and each qubit 1550_1 to 1550_N can be individually addressed because an operator (or controller) can address different qubits using time-division multiplexing. By controlling the 1-N quantum switch 100_1, the operator (controller) can match each drive or readout pulse (sent at different times) to the appropriate qubit readout system. The following explanation refers to the first microwave signal with the qubit frequency (e.g.,(To control qubit 1550_1 at time t1), the same applies analogously to microwave signals with the respective qubit frequencies to control qubits 1550_2 to 1550_N. At input IN1, the desired qubits are controlled. 1550 Microwave signals using time-division multiplexing to arrange resonator qubit systems 1520transmitted. For example, a first microwave signal with qubit frequency is transmitted at time t1 on transmission line 30_1 to drive qubit 1550_1, a second microwave signal with qubit frequency is transmitted at time t2 on transmission line 30_1 to drive qubit 1550_2, and so on, up to a final microwave signal at qubit frequency is transmitted at time tN on transmission line 30_N to drive qubit 1550_N. In one implementation, the transmission times of the microwave signals can have the relationship t1 < t2 < tN. In another implementation, the timings can be in a different order depending on the operation. Regardless of the order, the idea is that in Fig. 15 at any given time no more than one qubit readout system is accessed or addressed.

[0115] The first microwave signal at the qubit frequency for controlling qubit 1550_1 is sent to the broadband circulator / directional coupler. 1505 transmitted, which forwards the first microwave signal to the 1-N quantum switch / router 100_1. 1-N -Quantum switch / router 100_1 is (via a tunable filter) 20 ) configured to transmit the first microwave signal via transmission line 30_1 to qubit 1550_1 in the arrangement of resonator-qubit systems 1520 directs. Each tunable filter 20 In the 1-N quantum switch / router 100_1, it is configured in advance or during operation so that a specific microwave signal from the first to the last microwave signals according to the operation performed is sent to the respective qubit of the qubits. 1550 directs each microwave signal to its corresponding qubit 1550It is guided at a suitable qubit frequency. Accordingly, there is a tunable filter. 20 , which is connected to a respective transmission line 30_1 to 30_N, so that a tunable filter 20 is configured to deliver the intended microwave signal to its intended (one) qubit 1550 conducts, since the qubit frequency is related to the transmission of the associated tunable filter. 20 corresponds to the intended qubit. Each transmission line 30_1 to 30_N is equipped with a corresponding tunable filter. 20 connected. The qubit 1550_1 is controlled to a state by the first microwave signal with the qubit frequency for the qubit 1550_1, since the microwave signal at the qubit frequency for the qubit 1550_1 was guided on the transmission line 30_1 through the 1-N quantum switch / router 100_1 to the qubit 1550_1.

[0116] Similarly, at input IN1, a second microwave signal with the qubit frequency matching that of qubit 1550_2 is sent to the broadband circulator / directional coupler at time t2 to control qubit 1550_2. 1505 transmitted, which then directs the second microwave signal to the 1-N quantum switch / router 100_1, and the 1-N quantum switch / router 100_1 directs the second microwave signal via the tunable filter. 20 (which is configured to allow the qubit frequency of qubit 1550_2 to pass through) to qubit 1550_2 in the arrangement of resonator qubit systems 1520Qubit 1550_2 is switched to a state by the second microwave signal at the matching qubit frequency for qubit 1550_2, because the microwave signal at the qubit frequency for qubit 1550_2 was routed to qubit 1550_2 via the 1-N quantum switch / router 100_1 on transmission line 30_2. As described above, time t2 can be before or after t1 and / or before or after tN (depending on the processing sequence).

[0117] Similarly, at input IN1, a final microwave signal with the qubit frequency corresponding to qubit 1550_N is sent to the broadband circulator / directional coupler at time tN to control qubit 1550_N. 1505 transmitted, which then directs the last microwave signal to the 1-N quantum switch / router 100_1, and the 1-N quantum switch / router 100_1 directs the last microwave signal via the tunable filter. 20(which is configured to allow the qubit frequency to pass through that matches qubit 1550_N) to qubit 1550_N in the arrangement of resonator qubit systems 1520 Qubit 1550_N is switched to a state by the last microwave signal at the qubit frequency for qubit 1550_N, since the microwave signal at the qubit frequency for qubit 1550_N was routed to qubit 1550_N via transmission line 30_N through the N quantum switch / router 100_1. This time-division multiplexed process can be used to switch the qubits in the Fig. 15 to Fig. to head for 18.

[0118] As explained above, each individual qubit 1550_1 to 1550_N can be addressed at a different time t1, t2, ... tN by the respective first to last microwave signals to the desired qubits 1550_1 to 1550_N. Each of the qubits 1550_1 to 1550_N is addressed individually at a specific time according to a timing schedule. It should be noted that if the operator (or controller) performs gate operations (cross-resonance gates) between adjacent qubits, the operator (or controller) can send a qubit pulse to a specific qubit at the frequency of one of its neighbors (not its own frequency), which may occur in an implementation. After each qubit 1550_1 to 1550_N has been addressed, there is a reflected microwave signal. An example case is given for qubit 1550_1, but this applies analogously to qubits 1550_2 to 1550_N.After qubit 1550_1 is activated, the first microwave signal with the qubit frequency for qubit 1550_1 is sent back to the connected tunable filter on transmission line 30_1. 20 reflected in the 1-N quantum switch / router 100_1. Since the tunable filter is connected to the transmission line 30_1 20 Configured to allow the first microwave signal from qubit 1550_1 to pass through, the 1-N quantum switch / router 100_1 outputs the reflected first microwave signal (via the single terminal) to the broadband circulator / directional coupler. The circulator / directional coupler 1505 The reflected (outgoing) first microwave signal (according to the arrow) is directed to the 1-2 quantum switch 100_2. The quantum switch 100_2 is configured to receive the reflected first microwave signal using its tunable filter. 20 to the cold load / dump 1510outputs. The quantum switch 100_2 has two tunable filters. 20 , one of which is switched in such a way that it sends reflected microwave signals, which are drive pulses (as explained above), to the cold load / dump 1510 conducts, and one is switched in such a way that it sends reflected microwave signals, which are readout pulses, to the quantum-limited broadband amplifier. 350 guides (as will be explained later). As explained here, the tunable filters can 20 so that they transmit the desired frequencies via the respective magnetic flux generation lines. 730 Allow or reject.

[0119] It will now be explained how qubits 1555_1 to 1550_1 are read out by reading their corresponding readout resonators 1555_N to 1550_N in the arrangement of resonator-qubit systems 1555_1 to 1550_1. The process of reading out a qubit by reading its readout resonator to obtain the quantum information (state) of the qubit is clear to a person skilled in the art, and one or more embodiments of this process are described in the system. 1500 Explained for reading in reflection mode.

[0120] Each readout resonator 1555_1 up to readout resonator 1555_N can have its own readout resonator frequency, so that in an implementation all readout resonator frequencies are distinguishable from each other in the arrangement of the resonator qubit system 1520NThe readout resonator frequencies need not be different in another implementation; some may differ, and some may be the same, because the 1-N quantum switch 100_1 is configured to direct to the location where the microwave signals of the readout pulses are directed. The following explanation applies to the first microwave signal at the readout frequency (e.g., to read out readout resonator 1555_1 at time t1'), but is analogous for microwave signals at the readout resonator frequencies to read out readout resonators 1555_2 to 1555_N. Input IN1 is used to control the desired readout resonators. 1555 Microwave signals are applied to the array of resonator qubit systems using time-division multiplexing. 1520The transmission process continues. For example, a first microwave signal at the readout resonator frequency for reading out readout resonator 1555_1 is transmitted at time t1' on transmission line 30_1, a second microwave signal at the readout resonator frequency for reading out readout resonator 1555_2 is transmitted at time t2' on transmission line 30_1, up to a final microwave signal at the readout resonator frequency for reading out readout resonator 1555_N at time tN' on transmission line 30_N. The timing is determined by a controller depending on the operation or application being performed, and the timings are not identical.

[0121] At time t1', the first microwave signal with the readout frequency is used to read (i.e., to oscillate) the readout resonator 1555_1 to the broadband circulator / directional coupler. 1505transmitted, which directs the first microwave signal to the 1-N quantum switch / router 100_1. The 1-N Quantum switch / router 100_1 is (via the tunable filter) 20 ) configured to transmit the first microwave signal via transmission line 30_1 to the readout resonator 1555_1 in the arrangement of resonator-qubit systems 1520 directs. Each tunable filter 20 The 1-N quantum switch / router 100_1 can be configured (in advance and / or spontaneously) to control a specific selection of the first to last microwave signals from the respective readout resonators. 1555 It directs each microwave signal to its corresponding readout resonator. 1555 is being directed. Accordingly, there is a tunable filter. 20 , which is connected to a respective transmission line 30_1 to 30_N, so that a tunable filter 20is configured to transmit the intended microwave signal to its intended (one) readout resonator 1555 conducts, since the signal frequency is affected by the transmission of the tunable filter. 20 agrees with the intended selection resonator 1555 is connected (as well as to the intended qubit) 1550 is connected because the qubit signal frequency is linked to the transmission of the same tunable filter. 20 agrees with the intended qubit 1550 (is connected). Each transmission line 30_1 to 30_N is equipped with a respective tunable filter. 20in the 1-N quantum switch / router 100_1. Just as qubit 1550_1 is controlled to a state by the first microwave signal sent to qubit 1550_1, because the microwave signal frequency sent to qubit 1550_1 was routed on transmission line 30_1 from the 1-N quantum switch / router 100_1 to qubit 1550_1, the readout resonator 1555_1 is read by the first microwave signal sent to readout resonator 1555_1, since the microwave signal at the readout resonator frequency for readout resonator 1555_1 was routed from the 1-N quantum switch / router 100_1 to transmission line 30_1 to read out resonator 1555_1. In other words, the tunable filter connected to transmission line 30_1 20 can be tuned to transmit both the qubit driver pulse for qubit 1550_1 and the readout pulse for readout resonator 1555_1, while all other tunable filters 20These frequencies are rejected in the 1-N quantum switch / router 100_1.

[0122] Similarly, at input IN1, a second microwave signal with the readout resonator frequency is sent to the broadband circulator / directional coupler at time t2' to read out the readout resonator 1555_2. 1505 transmitted, which then directs the second microwave signal to the 1-N quantum switch / router 100_1, and the 1-N quantum switch / router 100_1 directs the second microwave signal via the tunable filter. 20 (which is configured to allow the signal frequency to pass through in order to read out the readout resonator 1555_2) to the readout resonator 1555_2 in the arrangement of resonator qubit systems 1520The readout resonator 1555_2 is read by the second microwave signal at the readout resonator frequency for the readout resonator 1555_2, since the microwave signal at the readout resonator frequency for the readout resonator 1555_2 was transmitted on the transmission line 30_2 from the 1-N quantum switch / router 100_1 to the readout resonator 1555_2. Once qubit 1550_2 has been driven into a state by the first microwave signal sent to qubit 1550_2, because the microwave signal frequency sent to qubit 1550_2 was routed on transmission line 30_2 from the 1-N quantum switch / router 100_1 to qubit 1550_2, readout resonator 1555_2 is read (i.e., set into oscillation) by the first microwave signal sent to readout resonator 1555_2, because the microwave signal at the readout resonator frequency for readout resonator 1555_2 was routed on transmission line 30_2 from the 1-N quantum switch / router 100_1 to read out resonator 1555_2.In other words, the tunable filter connected to transmission line 30_2. 20 can be tuned to transmit both the qubit drive pulse for qubit 1550_2 and the readout pulse for readout resonator 1555_2, while all other tunable filters 20 These frequencies are rejected in the 1-N quantum switch / router 100_1.

[0123] Similarly, at input IN1, a final microwave signal with the readout resonator frequency is sent to the broadband circulator / directional coupler at time tN' for reading the readout resonator 1555_N. 1505 transmitted, which then directs the last microwave signal to the 1-N quantum switch / router 100_1, and the 1-N quantum switch / router 100_1 directs the last microwave signal via the tunable filter. 20(which is configured to allow the signal frequency to pass through in order to read the readout resonator 1555_N) to the readout resonator 1555_N in the arrangement of resonator qubit systems 1520The readout resonator 1555_N is read by the last microwave signal at the readout frequency for the readout resonator 1555_N, since the microwave signal at the readout resonator frequency for the readout resonator 1555_N was routed on the transmission line 30_N through the 1-N quantum switch / router 100_1 to the readout resonator 1555_N. Once the qubit 1550_N has been driven into a state by the first microwave signal sent to the qubit 1550_N, because the microwave signal frequency sent to the qubit 1550_N was routed on the transmission line 30_N from the 1-N quantum switch / router 100_1 to the qubit 1550_N, the readout resonator 1555_N is read by the first microwave signal sent to the readout resonator 1555_N, since the microwave signal at the readout resonator frequency for the readout resonator 1555_N was routed on the transmission line 30_N from the 1-N quantum switch / router to the readout resonator 1555_N.In other words, the tunable filter connected to the 30_N transmission line. 20 can be tuned to transmit both the qubit drive pulse for qubit 1550_N and the readout pulse for readout resonator 1555_N, while all other tunable filters 20 These frequencies are rejected in the 1-N quantum switch / router 100_1.

[0124] As explained above, each individual readout resonator 1555_1 to 1555_N can be read by the respective first to last microwave signals sent to the desired readout resonator 1555_1 to 1555_N at different times t1', t2', ... tN'. Each of the readout resonators 1555_1 to 1555_N is read individually according to the timing schedule. After all readout resonators 1555_1 to 1555_N have been read (i.e., brought into resonance), a reflected microwave signal is produced. An example is given for readout resonator 1555_1, but the same applies analogously to readout resonators 1555_2 to 1555_N. After the readout resonator 1555_1 has been read, the first microwave signal at the readout resonator frequency for the readout resonator 1555_1 is fed to the associated tunable filter on the transmission line 30_1. 20reflected in the 1-N quantum switch / router 100_1. Since the tunable filter is connected to the transmission line 30_1 20 Configured to allow the first microwave signal to pass through at the readout resonator frequency of the readout resonator 1555_1, the 1-N quantum switch / router 100_1 outputs the reflected first microwave signal (via the single terminal) to the broadband circulator / directional coupler. 1505 off. The broadband circulator / directional coupler 1505 The reflected (outgoing) first microwave signal is directed to the 1-2 quantum switch 100_2. The quantum switch 100_2 is configured to send the reflected first microwave signal to the quantum-limited broadband amplifier. 350 outputs by using the tunable filter 20 passes through, which is connected to the port that connects it to the quantum-limited broadband amplifier 350 outputs. As stated above, the quantum switch 100_2 has two tunable filters.20 , one of which is switched to allow reflected microwave signals to pass through, which are the drive pulses, and one of which is switched to allow reflected microwave signals to pass through, which are the readout pulses.

[0125] The 1 -2-Quantum switch 100_2 and the cold load / dump 1510 are optional and shown with dashed lines. In one embodiment, the broadband circulator / directional coupler can 1505 directly with the quantum-limited broadband amplifier 350 be connected, and there is no 1-2 quantum switch 100_2 and no cold load / dump 1510 present. In this case, the pump control becomes the quantum-limited broadband amplifier. 350 switched on when a reflected microwave signal (i.e., reflected readout pulse) is received from one of the readout resonators 1555_1 to 1555_N from the circulator 1505in the quantum-limited broadband amplifier 350 occurs, so that the reflected microwave signals (i.e., reflected drive / qubit pulses) from the readout resonators 1555 to be amplified. The pump control for the quantum-limited amplifier. 350 is switched off when a reflected microwave signal (i.e., a reflected drive / qubit pulse) from one of the qubits 1550_1 to 1550_N is received by the circulator 1505 in the quantum-limited broadband amplifier 350 occurs, so that the reflected microwave signals (reflected drive / qubit pulses) from the qubits 1550 The timing is not amplified. The timing is predetermined or dynamically controlled by a controller to switch the pump on to the quantum-limited amplifier. 350 determined to reflect the microwave signal (i.e., the reflected readout pulse) from the readout resonators 1555to amplify the pump and to turn it off when reflected drive / qubit pulses are present. The controller may include a memory containing computer-executable instructions and one or more processors configured to execute the computer-executable instructions according to the embodiments described herein.

[0126] In Fig. 15 properties of the superconducting quantum switch / router can include: near-blind transmission > -0.04 dB, reflection less than -20 dB, and a large on / off ratio > 20 dB. When designing the system 1500 The superconducting quantum switch / router is lossless, switches quickly (~ns), is scalable to more than two connections, and has a large dynamic range > -80 dBm to support cross-resonance microwaves, and is broadband (covering the qubit and readout frequencies required in the resonator-qubit system array). 1520(should be used).

[0127] Fig. 16 is a system 1600 both for qubit addressing and qubit readout according to one or more embodiments. The system 1600 This illustrates operation in reflection mode, where different input and output lines (I / O lines) (i.e., transmission lines) are used to read out the qubits and qubit pulses. In this case, input IN1 is used to read out the readout resonators. 1555 used, while input IN2 is used to control the qubits 1550 is used. The system 1600 contains the same elements as the system 1500 with the exception that the system 1600 the 1-2 quantum switch in Fig. 15 does not contain it. The system 1600It contains two broadband circulators / directional couplers designated 1505_1 and 1505_2, contains two 1-N quantum switches / routers designated 100_1 and 100_2, and two input lines designated as input IN1 and input IN2.

[0128] For better understanding, and not as a limitation, certain features in the system are 1600 This is explained with regard to the readout side and the qubit control / driver side. On the readout side, input IN1 is connected to the broadband circulator / directional coupler 1505_1 via one terminal, and the broadband circulator / directional coupler 1505_1 is connected via another terminal to the 1-N quantum switch / router 100_1, which is used to read the readout resonator. 1555 The 1-N quantum switch / router 100_1 used for reading is connected via transmission lines 30_1 to 30_N to the arrangement of resonator qubit systems. 1520connected, as explained above. The broadband circulator / directional coupler 1505_1 is connected to the quantum-limited broadband amplifier. 350 connected when readout pulses are reflected from the readout resonators 1555_1 to 1555_N.

[0129] On the qubit control / driver side, input IN2 is connected to the broadband circulator / direction coupler 1505_2 via one connector, and via another connector the broadband circulator / direction coupler 1505_2 is connected to the 1-N quantum switch / router 100_2, which is used to drive / control the qubits. 1550 The 1-N quantum switch / router 100_2, which is used for addressing / controlling qubits, is connected via transmission lines 30_1 to 30_N to the arrangement of resonator-qubit systems. 1520 connected, as explained above. The broadband circulator / directional coupler 1505_2 is connected to the cold load / dump 1510 connected when control pulses are reflected.

[0130] Addressing Qubits 1550 and the reading of readout resonators 1555 This is done analogously to the system 1500 in Fig. 15 with the exception that two separate feed lines (transmission lines) are used for input IN1 for the readout pulses and for input IN2 for the qubit / drive pulses. In the system 1600 from Fig. Section 16 describes the first microwave signal applied to qubit 1550_1 (e.g., to activate qubit 1550_1 at time t1). However, it applies analogously to microwave signals at the qubit signal frequencies to activate qubits 1550_2 to 1550_N. The desired qubits are activated at input IN2. 1550 Microwave signals are applied to the array of resonator qubit systems using time-division multiplexing. 1520The signals are transmitted. For example, a first microwave signal to control qubit 1550_1 is transmitted at time t1 on transmission line 30_1. The signal to control qubit 1550_2 is transmitted at time t2 on transmission line 30_1, up to a final microwave signal to control qubit 1550_N at time tN on transmission line 30_N.

[0131] In Fig. 16. The first microwave signal to control qubit 1550_1 is transmitted to the broadband circulator 1505_2, which forwards the first microwave signal to the 1-N quantum switch / router 100_2. The 1-N quantum switch / router 100_2 is (via the tunable filter) 20 ) configured to transmit the first microwave signal via transmission line 30_1 on the qubit control / driver side to qubit 1550_1 in the resonator-qubit system arrangement 1520 directs. Each filter 20The 1-N quantum switch / router 100_1 is configured (e.g., pre-defined and / or spontaneously by the controller) to output a specific microwave signal from the first to the last microwave signals according to its qubit signal frequency to the corresponding qubit frequency. 1550 directs each microwave signal to its corresponding qubit 1550 is directed. Accordingly, there is a tunable filter. 20 , which is connected to a respective transmission line 30_1 to 30_N on the qubit control / driver side, so that the tunable filter 20 is configured to deliver the intended microwave signal to its intended qubit 1550 conducts because the qubit signal frequency is affected by the transmission of the tunable filter. 20 agrees with the intended qubit 1550 Each transmission line 30_1 to 30_N is connected with a corresponding tunable filter. 20of the 1-N quantum switch / router 100_2. Qubit 1550_1 is controlled to a state by the first microwave signal sent to qubit 1550_1, since the microwave signal for qubit 1550_1 was routed to qubit 1550_1 via the 1-N quantum switch / router 100_2 on transmission line 30_1 (the qubit control side).

[0132] Similarly, at input IN2, a second microwave signal sent to qubit 1550_2 is transmitted at time t2 to the broadband circulator / directional coupler 1505_2, which then directs the second microwave signal to the 1-N quantum switch / router 100_2, and the 1-N quantum switch / router 100_2 directs the second microwave signal via the tunable filter. 20 (which is configured to allow the qubit signal frequency of qubit 1550_2 to pass through) to qubit 1550_2 in the arrangement of the resonator qubit systems 1520The qubit 1550_2 is set to a state by the second microwave signal for the qubit 1550_2, since the microwave signal sent to the qubit 1550_2 was routed on the transmission line 30_2 on the qubit driver side through the 1-N quantum switch / router 100_2 to the qubit 1550_2.

[0133] Similarly, at input IN2, a final microwave signal 1550_N sent to the qubit is transmitted at time tN to the broadband circulator / directional coupler 1505_2, which then directs the final microwave signal to the 1-N quantum switch / router 100_2, and the 1-N quantum switch / router 100_2 directs the final microwave signal via the tunable filter. 20 (which is configured to allow the qubit signal frequency of qubit 1550_N to pass through) to qubit 1550_N in the arrangement of resonator qubit systems 1520The qubit 1550_N is controlled into a state by the last microwave signal for the qubit 1550_N, since the microwave signal sent to the qubit 1550_N was routed on the transmission line 30_N on the qubit control side through the 1-N quantum switch / router 100_2 to the qubit 1550_N.

[0134] As explained above, each individual qubit 1550_1 to 1550_N can be connected to input IN2 (it should be noted that in Fig. (Input IN1 is used) on the qubit control side are controlled by the respective first to last microwave signals, which are sent to the desired qubits 1550_1 to 1550_N at different times t1, t2,... tN. Each of the qubits 1550_1 to 1550_N is addressed individually according to a timing schedule. After each qubit 1550_1 to 1550_N has been addressed, a reflected microwave signal is generated. As explained above, an example case is given for qubit 1550_1, but it applies analogously to qubits 1550_2 to 1550_N. After qubit 1550_1 is addressed, the first microwave signal sent to qubit 1550_1 is routed from transmission line 30_1 (on the qubit addressing / controlling side) in the 1-N quantum switch / router 100_2 to the connected tunable filter. 20 reflected. Since the tunable filter 20The 1-N quantum switch / router 100_2, which is connected to the transmission line 30_1 (on the qubit drive side) and is configured to pass the frequency of the first microwave signal of qubit 1550_1, outputs the reflected first microwave signal (via the single connection) to the broadband circulator / directional coupler 1505_2. The broadband circulator / directional coupler 1505_2 routes the reflected (outgoing) first microwave signal to the cold load / dump. 1510 Unlike Fig. However, 15 will be in Fig. 16 no 1-2 quantum switch used because Fig. It has 16 separate inputs, IN1 and IN2. As explained here, the tunable filters 20 They are tuned to allow desired frequencies to pass through or via respective magnetic flux generation lines. 730 reject.

[0135] The following is an explanation of the individual readout of qubits 1550_1 to 1550_N by reading their respective readout resonators 1555_1 to 1555_N in the arrangement of resonator-qubit systems. 1520 , which is done using input IN1 on the readout side.

[0136] The following explanation concerns the first microwave signal at the readout frequency (e.g., for reading out readout resonator 1555_1 at time t1'), but applies analogously to microwave signals at the readout resonator frequencies for reading out readout resonators 1555_2 to 1555_N. The desired readout resonators are controlled at input IN1. 1555 Microwave signals are applied to the array of resonator qubit systems using time-division multiplexing. 1520transmitted. For example, a first microwave signal with the readout frequency for reading the readout resonator 1555_1 is sent at time t1' on the transmission line 30_1 on the readout side, and a second microwave signal with the readout frequency for reading the readout resonator 1555_2 is sent at time t2' on the transmission line 30_1 on the readout side, up to a last microwave signal which is sent at the readout frequency for reading the readout resonator 1555_N at time tN' on the transmission line 30_N on the readout side.

[0137] At time t1', the first microwave signal with the readout frequency for reading the readout resonator 1555_1 is transmitted to the broadband circulator 1505_1, which directs the first microwave signal to the 1-N quantum switch / router 100_1. The 1-N quantum switch / router 100_1 is (via the tunable filter) 20) configured so that it transmits the first microwave signal via the transmission line 30_1 on the readout side to the readout resonator 1555_1 in the arrangement of resonator-qubit systems 1520 directs. Each tunable filter 20 The 1-N quantum switch / router 100_1 is configured (e.g., pre-defined and / or spontaneously determined by the controller) to send a specific selection of the first to last microwave signals to the respective readout resonator according to its readout frequency. 1555 It directs each microwave signal to its corresponding readout resonator. 1555 is directed. Accordingly, there is a tunable filter. 20 , which is connected to a respective transmission line 30_1 to 30_N on the readout side, so that a tunable filter 20 is configured to transmit the intended microwave signal to its intended (one) readout resonator 1555conducts, since the readout frequency is linked to the transmission of the tunable filter. 20 agrees with the intended selection resonator 1555 is connected. In Fig. 16 must have this one tunable filter 20 The 1-N quantum switch / router 100_1 is configured to pass the first microwave signal at the readout frequency of resonator 1555_1, but does not need to be configured to pass any microwave signal with a qubit frequency matching the intended qubit 1550_1 connected to readout resonator 1555_1. Each transmission line 30_1 to 30_N on the readout side is equipped with a tunable filter. 20 connected in the 1-N quantum switch / router 100_1.

[0138] Similarly, at input IN1 on the readout side, a second microwave signal with the readout frequency of the readout resonator 1555_2 at time t2' is transmitted to the broadband circulator / directional coupler 1505_1, which then forwards the second microwave signal to the 1-N quantum switch / router 100_1. 1-N -Quantum switch / router 100_1 routes the second microwave signal through the tunable filter 20 (which is configured to allow the readout frequency of the readout resonator 1555_2 to pass through) to the readout resonator 1555_2 in the arrangement of resonator qubit systems 1520 The readout resonator 1555_2 is read by the second microwave signal with the readout frequency for the readout resonator 1555_2, since the microwave signal at the readout frequency for the readout resonator 1555_2 was passed on the readout side 30_2 through the 1-N quantum switch / router 100_1 to the readout resonator 1555_2.

[0139] Similarly, at input IN1 on the readout side, a final microwave signal at the readout frequency of the readout resonator 1555_N at time tN' is transmitted to the broadband circulator / directional coupler 1505_1, which then forwards the final microwave signal to the 1-N quantum switch / router 100_1. 1-N -Quantum switch / router 100_1 routes the last microwave signal through the tunable filter. 20 (which is configured to allow the qubit frequency of the readout resonator 1555_N to pass through) to the readout resonator 1555_N in the arrangement of resonator-qubit systems 1520The readout resonator 1555_N is read by the last microwave signal at the readout frequency for the readout resonator 1555_N, since the microwave signal at the readout frequency for the readout resonator 1555_N was routed on the transmission line 30_N on the readout side through the 1-N quantum switch / router 100_1 to read out the resonator 1555_N.

[0140] As explained above, each individual readout resonator 1555_1 to 1555_N can be read at a different time t1', t2', ... tN' by the respective first to last microwave signal with a readout frequency that matches the desired readout resonator 1555_1 to 1555_N. Each of the readout resonators 1555_1 to 1555_N is read individually according to the timing scheme. After all readout resonators 1555_1 to 1555_N have been read (i.e., brought into resonance), a reflected microwave signal is present. An example is given for readout resonator 1555_1, but the procedure applies analogously to readout resonators 1555_2 to 1555_N. After reading the readout resonator 1555_1, the first microwave signal with the readout frequency for the readout resonator 1555_1 of the arrangement of resonator qubit systems is 1520 on the transmission line 30_1 (on the readout side) to the connected tunable filter 20reflected in the 1-N quantum switch / router 100_1. Since the tunable filter 20 The 1-N quantum switch / router 100_1, which is connected to the transmission line 30_1 (on the readout side), is configured (e.g., in advance and / or spontaneously by the controller) to allow the first microwave signal with the readout frequency of the readout resonator 1555_1 to pass through. The reflected first microwave signal (via the single connection) is then output by the broadband circulator / directional coupler 1505_1. The broadband circulator / directional coupler 1505_1 then directs the reflected (outgoing) first microwave signal to the quantum-limited broadband amplifier. 350 As mentioned above, the 1-N quantum switch / router directs 100_1 reflected microwave signals (i.e., reflected readout pulses from the respective readout resonators 1555_1 to 1555_N) to the quantum-limited broadband amplifier for amplification. 350 .

[0141] Similarly, each of the reflected microwave signals (which are drive pulses reflected from the respective qubits 1550_1 to 1550_N onto transmission lines 30_1 to 30_N on the qubit drive side) is processed by the arrangement of resonator qubit systems 1520 The signal is transmitted back to the 1-N quantum switch / router 100_2. The 1-N quantum switch / router 100_2 transmits the reflected microwave signals of the drive pulses to the broadband circulator / directional coupler 1505_2, which then transmits the reflected microwave signals of the drive pulses to the cold load / dump. 1510 leads.

[0142] Among the technical advantages of the system 1600 in Fig. 16 compared to the system 1500The following may be included: 1) The 1-N quantum switch / router 100_1 on the readout side can be designed differently than the 1-N quantum switch / router 100_2 on the qubit control side. 2) It is not necessary to route outgoing readout and qubit pulses on different paths, and it is not necessary to operate the pump applied to the quantum-limited broadband amplifier. The trade-off when using the system 1600 (in contrast to the system 1500 ) is twice (2x) the number of input lines, twice (2x) the number of circulators, and twice (2x) the number of 1-N quantum switches / routers.

[0143] Fig. 17 is a system 1700 , to both address and read qubits according to one or more embodiments. The system 1700This illustrates operation in reflection mode, where different input and output lines (I / O lines) (i.e., transmission lines) are used when reading the readout resonators (for reading the qubits) with readout pulses and when driving / controlling the qubits with qubit pulses.

[0144] Operating the microwave signals as qubit drive pulses, each controlling qubits 1550_1 to 1550_N in the arrangement of resonator-qubit systems 1520 to target, was in Fig. 16 explains and applies to Fig. 17. Similarly, the process of transmitting the reflected microwave signals of the qubit drive pulses to the cold load / dump was described. 1510 in Fig. 16 explains and applies to Fig. 17.

[0145] On the readout side, the signal distributor (combiner) has 1000_1 in the system. 1700 from Fig. 17 the 1-N quantum switch / router 100_1 of Fig. 17 replaced. In the system 1700The first to last microwave signals at the readout frequencies (of readout resonators 1555_1 to 1555_N) can all be simultaneously applied via frequency-division multiplexing to input IN1 on the readout side, and / or any desired microwave signals at the desired readout frequencies (of readout resonators 1555_1 to 1555_N) can be applied. The first to last microwave signals at the readout resonator frequencies (of readout resonators 1555_1 to 1555_N) are routed to the broadband circulator / directional coupler 1505_1, which routes the first to last microwave signals at the readout resonator frequencies (of readout resonators 1555_1 to 1555_N) to the signal distribution unit 1000_1.The signal distribution unit 1000_1 is configured to use frequency division multiplexing to receive the different readout resonator frequencies for different microwave signals at a single connection (simultaneously), and is configured to distribute the different readout resonator frequencies for the first to last microwave signals (simultaneously) to several transmission lines 30_1 to 30_N, which are connected to the arrangement of resonator qubit systems. 1520are connected. The individual bandpass filters 105_1 to 105_N of the signal distribution unit 1000_1 are each connected (via connections) to transmission lines 30_1 to 30_N (on the readout side), so that the bandpass filter 105_1 is connected to the transmission line 30_1 (on the readout side), up to the bandpass filter 105_N, which is connected to the transmission line 30_N (on the readout side).In parallel, the signal distribution unit 1000_1 is configured to route the first microwave signal with the readout resonator frequency of readout resonator 1555_1 via transmission line 30_1 to readout resonator 1555_1, to route the second microwave signal with the readout resonator frequency of readout resonator 1555_2 via transmission line 30_2 to readout resonator 1555_2, and to route the last microwave signal with the readout resonator frequency of readout resonator 1555_N via transmission line 30_N to readout resonator 1555_N. This is because each of the bandpass filters... 105 is individually configured in advance to select a single readout resonator frequency (of a single readout resonator). 1555) to allow microwave signals to pass through, so that the bandpass filter 105_1 is configured to allow the first microwave signal with the readout frequency of the readout resonator 1555_1 to pass through, the bandpass filter 105_2 is configured to allow the second microwave signal with the readout frequency of the readout resonator 1555_2 to pass through, up to the bandpass filter 105_N, which is configured to allow the last microwave signal with the readout frequency of the readout resonator 1555_N to pass through. Accordingly, each first to last microwave signal causes its respective readout resonator 1555_1 to 1555_N to resonate at a readout resonator frequency, thereby reflecting the first to last microwave signals (simultaneously) along the transmission lines 30_1 to 30_N to reach the signal distribution unit 1000_1.It should be noted that the measurements can be performed in parallel (simultaneously), but it is not necessary for the readout to occur at the same time or for all measurements to be taken before the second measurement round. In the example scenario, the signal distribution unit 1000_1 combines the reflected first to last microwave signals (at the respective readout resonator frequencies of the readout resonators 1555_1 to 1555_N) and outputs the combined reflected microwave signals to the broadband circulator / directional coupler 1505_1. The broadband circulator / directional coupler 1505_1 then directs the combined reflected first to last microwave signals (each at the readout resonator frequencies of the readout resonators 1555_1 to 1555_N) to the quantum-limited broadband amplifier. 350 .

[0146] The process of controlling the qubits with microwave signals (as qubit control pulses) is the same as in Fig. 16 and will be in Fig. 17 not repeated. The internal details of the superconducting microwave signal distributor 1000_1 can be found in the explanation of the superconducting microwave signal distributor / combiner unit. 1000 can be found in the Fig. 10 to Fig. 14.

[0147] Technical advantages of Fig. 17 (e.g., using the superconducting, lossless, and matched signal distribution unit) 1000 ) compared to the Fig. 15 and Fig. 16 include 1) simultaneous readout of the readout resonators and 2) the lack of need to route outgoing readout and qubit pulses onto different paths. The trade-off of using the system 1700 (in contrast to the system 1500 ) consists of twice (2x) the number of input lines, twice (2x) the number of circulators and twice (2x) the number of 1-N quantum switches / routers.

[0148] Fig. 18 is a system 1800for addressing and reading qubits according to one or more embodiments. The system 1800 This illustrates a readout in transmission mode. The system 1800 It has various input and output lines (I / O lines) (i.e., transmission lines) for reading the readout resonators (for reading the qubits) with readout pulses and for driving / controlling the qubits with qubit pulses. The system 1800 can be used with the system 1700 be identical with the exception that in the system 1800 The reading out to measure the qubits is done in transmission mode using a second lossless and matched signal combiner unit (where frequency division multiplexing is used).

[0149] In the system 1700 from Fig. 17. The reflected microwave signals (as readout signals) are sent back by the microwave signal distribution unit 1000_1. In Fig. 18 However, the microwave signals are transmitted as readout signals (at the readout resonator frequencies) to a microwave signal combiner unit 1000_2, which combines all transmitted microwave signals at the readout resonator frequencies and sends the combined microwave signals to the quantum-limited broadband amplifier 350 outputs for amplification and subsequent measurement.

[0150] Since the input IN2 receives microwave signals as qubit control / drive pulses for qubits 1550 and the reflection of the microwave signals for the qubit control / drive pulses are the same as in the Fig. 16 and Fig. Section 17 explains the qubit addressing / control in Fig. 18 not repeated.

[0151] An example of reading data in transmission mode will now be given in Fig. 18 explained. In the system 1800The first to last microwave signals at the readout resonator frequencies (of readout resonators 1555_1 to 1555_N) can all be simultaneously applied to input IN1 on the readout side via frequency division multiplexing. The first to last microwave signals at the readout resonator frequencies (of readout resonators 1555_1 to 1555_N) are routed to the broadband circulator / directional coupler 1505_1, which then routes the first to last microwave signals at the readout resonator frequencies (of readout resonators 1555_1 to 1555_N) to the signal distribution unit 1000_1, as explained above.The signal distribution unit 1000_1 is configured to use frequency division multiplexing to receive the different readout resonator frequencies for different microwave signals (at a single connection) (simultaneously), and is configured to distribute the first to last microwave signals (according to their readout resonator frequencies) (of the readout resonators 1555_1 to 1555_N) (simultaneously) to several transmission lines 30_1 to 30_N, which are connected to the arrangement of the resonator qubit system. 1520are connected. The individual bandpass filters 105_1 to 105_N of the signal distribution unit 1000_1 are each connected (via connections) to transmission lines 30_1 to 30_N (on the readout side), so that the bandpass filter 105_1 is connected to the transmission line 30_1 (on the readout side), up to the bandpass filter 105_N, which is connected to the transmission line 30_N (on the readout side). In parallel, the signal distribution unit 1000_1 is configured to transmit the first microwave signal with the readout resonator frequency of the readout resonator 1555_1 via the transmission line 30_1 to the readout resonator 1555_1, to transmit the second microwave signal with the readout resonator frequency of the readout resonator 1555_2 via the transmission line 30_2 to the readout resonator 1555_2, and to transmit the last microwave signal with the readout resonator frequency of the readout resonator 1555_N via the transmission line 30_N to the readout resonator 1555_N.This is because each of the bandpass filters . 105 It is individually configured in advance to allow a single readout resonator frequency to pass through, which corresponds to a single readout resonator. 1555for microwave signals, so that the bandpass filter 105_1 is configured to allow the first microwave signal with the readout frequency of the readout resonator 1555_1 to pass through, the bandpass filter 105_2 is configured to allow the second microwave signal with the readout frequency of the readout resonator 1555_2 to pass through, up to the last bandpass filter 105_N, which is configured to allow the last microwave signal at the readout frequency of the readout resonator 1555_N to pass through. Accordingly, each first to last microwave signal causes its respective readout resonator 1555_1 to 1555_N to resonate at a readout resonator frequency, thereby transmitting the first to last microwave signal (simultaneously) via transmission lines to reach the signal distribution unit 1000_2.The signal distribution unit 1000_2 combines the first to last microwave signals (of the respective readout resonator frequencies of the readout resonators 1555_1 to 1555_N) and (simultaneously) transmits the combined reflected microwave signals via a single transmission line to the quantum-limited broadband amplifier. 350 for amplification and later measurement.

[0152] The internal details of the superconducting microwave signal distributor / contributor 1000_1 and 1000_2 can be found in the explanation of the superconducting unit of the microwave signal distributor / combiner. 1000 can be found in the Fig. 10 to Fig. 14 took place.

[0153] Regarding the technical advantages of the system 1800 in Fig. 1) simultaneous reading of the readout resonators and 2) circulators on the readout side are not required.

[0154] Fig. 19 is a schedule 1900a procedure for configuring a system 1500 for addressing and reading qubits according to one or more embodiments. In the block 1905 is a first lossless microwave switch 100_1 (in Fig. 15) with a quantum system (e.g. the arrangement of resonator-qubit systems) 1520 ) connected. In the block 1910 Can a second lossless microwave switch 100_2 (in Fig. 15) to be connected to the first lossless microwave switch 100_1. In the block 1915 can a quantum-limited amplifier 350 to be connected to the second lossless microwave switch 100_2.

[0155] A circulator 1505 is configured to connect the first lossless microwave switch 100_1 with the second lossless microwave switch 100_2 in Fig. 15 connects. The circulator 1505It is configured to connect input IN1 to the first lossless microwave switch 100_1. The second lossless microwave switch 100_2 is configured to connect to the quantum-limited amplifier. 350 and connecting to a load dump 1510 in Fig. 15 selects. The quantum system (e.g., the arrangement of resonator-qubit systems) 1520 ) contains a first qubit 1550_1, which is connected at a first terminal to a first readout resonator 1555_1, a second qubit 1550_2, which is connected at a second terminal to a second readout resonator 1555_2, up to a last qubit 1550_N, which is connected at a last terminal to a last readout resonator 1555_N, each from first to last qubit 1550_1 to 1550_N having a first to last qubit frequency.

[0156] Fig. 20 is a schedule 2000a procedure for configuring a system 1600 for addressing and reading qubits according to one or more embodiments. In Fig. 16 is in the block 2005 a first lossless microwave switch 100_1 with a quantum system (e.g. the arrangement of resonator-qubit systems) 1520 ) connected, wherein a first input IN1 can be connected to the first lossless microwave switch 100_1, and a quantum-limited amplifier 350 can be connected to the first lossless microwave switch 100_1. In Fig. 16 is in the block 2010 a second lossless microwave switch 100_2 with the quantum system (e.g. the arrangement of resonator-qubit systems) 1520) connected, wherein a second input IN2 can be connected to the second lossless microwave switch 100_2, wherein the second input IN2 is configured to drive the quantum system, and the first input IN1 is configured to read the quantum system.

[0157] In Fig. 16 is a first circulator 1505_1 configured to connect the first input IN1 to the first lossless microwave switch 100_1, and is configured to connect the quantum-limited amplifier 350 a second circulator 1505_2 is configured to connect the second input IN2 to the second lossless microwave switch 100_2 and perform a load dump. 1510 with the second lossless microwave switch 100_2 in Fig. 16 connects. The quantum system (e.g., the arrangement of resonator-qubit systems) 1520The array contains a first qubit 1550_1, which is connected at a first terminal to a first readout resonator 1555_1, a second qubit 1550_2, which is connected at a second terminal to a second readout resonator 1555_2, up to a last qubit 1550_N, which is connected at a last terminal to a last readout resonator 1555_N. Each qubit from 1550_1 to 1550_N has its own first to last qubit frequency. The first to last qubits 1550_1 to 1550_N are driven via the second lossless microwave switch 100_2, and the first to last readout resonators 1555_1 to 1555_N are read via the first lossless microwave switch 100_1.

[0158] Fig. 21 is a schedule 2100 a procedure for configuring a system 1700 for addressing and reading qubits according to one or more embodiments. In the block 2105is a lossless microwave signal distributor 1000_1 with a quantum system (e.g., the arrangement of resonator-qubit systems) 1520 ) connected, with a first input IN1 connected to the lossless microwave signal distributor 1000_1 in Fig. 17 can be connected. In the block 2110 is a lossless microwave switch 100_2 with the quantum system (e.g. the arrangement of resonator-qubit systems) 1520 ) connected, whereby a second input IN2 can be connected to the lossless microwave switch 100_2. The second input IN2 is configured to control the quantum system (e.g., the arrangement of resonator-qubit systems). 1520 ) is controlled via the lossless microwave switch 100_2, and the first input IN1 is configured to read the quantum system via the lossless microwave signal distributor 1000_1.

[0159] A first circulator 1505_1 is configured to connect the first input IN1 to the lossless microwave signal distributor 1000_1, and is configured to drive a quantum-limited amplifier. 350 with the lossless microwave signal distributor 1000_1 in Fig. 17 connects. A second circulator 1505_2 is configured to connect the second input IN2 to the lossless microwave switch 100_2 and perform a load dump. 1510 connects to the lossless microwave switch 100_2. The quantum system (e.g., the arrangement of resonator-qubit systems) 1520The array contains a first qubit 1550_1, which is connected at a first terminal to a first readout resonator 1555_1, a second qubit 1550_2, which is connected at a second terminal to a second readout resonator 1550_2, up to a last qubit 1550_N, which is connected at a last terminal to a last readout resonator 1555_N. Each qubit from 1550_1 to 1550_N has its own frequency. The first and last qubits 1550_1 to 1550_N are controlled via the lossless microwave switch 100_2, while the first and last readout resonators 1555_1 to 1555_N are read out via the lossless microwave signal distributor 1000_1.

[0160] Fig. 22 is a schedule 2200 a procedure for configuring a system 1800 for addressing and reading qubits according to one or more embodiments. In the block 2205is a lossless microwave signal distributor 1000_1 with a quantum system (e.g., the arrangement of resonator-qubit systems) 1520 ) connected, with a first input IN1 connected to the lossless microwave signal distributor 1000_1 of Fig. 18 is connected. In the block 2210 is a lossless microwave switch 100_2 with the quantum system (e.g. the arrangement of resonator-qubit systems) 1520 ) connected, with a second input IN2 connected to the lossless microwave switch 100_2 from Fig. 18 can be connected. The second input IN2 is configured to control the quantum system via the lossless microwave switch 100_2. In the block 2215A lossless microwave signal combiner 1000_2 is connected to the quantum system, wherein the first input IN1 is configured to connect the quantum system via the lossless microwave signal distributor 1000_1 and the lossless microwave signal combiner 1000_2. Fig. 2 reads out.

[0161] A quantum-limited amplifier 350 is connected to the lossless microwave signal combiner 1000_2 to amplify the transmitted microwave signals of the readout pulses. A circulator 1505_2 is configured to connect the second input IN2 to the lossless microwave switch 100_2 and perform a load dump. 1510 with the lossless microwave switch 100_2 from Fig. 18 connects. The quantum system (e.g., the arrangement of resonator-qubit systems) 1520) contains a first qubit 1550_1, which is connected at a first terminal to a first readout resonator 1555_1, a second qubit 1550_2, which is connected at a second terminal to a second readout resonator 1555_2, up to a last qubit 1550_N, which is connected at a last terminal to a last readout resonator 1555_N, each having a first to last qubit frequency from 1550_1 to 1550_N. The first to last qubits 1550_1 to 1550_N are controlled via the lossless microwave switch 100_2. Each of the first to the last readout resonator 1555_1 to 1555_N can be read out simultaneously via the lossless microwave signal distributor 1000_1 and the lossless microwave signal combiner 1000_2.

[0162] The term "approximately" and variations thereof are intended to include the degree of error in measuring the specified quantity based on the equipment available at the time the application was filed. For example, "approximately" may include a range of ± 8%, 5%, or 2% of a given quantity.

[0163] Aspects of the present invention are described here with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the invention. It is understood that each block of the flowcharts and / or block diagrams, and of combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer-readable program instructions.

[0164] The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this context, each block in the flowchart or block diagrams can represent a module, segment, or section of instructions that includes one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions specified in the block may not occur in the order shown in the figures. For example, two blocks shown sequentially may actually be executed substantially simultaneously, or the blocks may occasionally be executed in reverse order, depending on the functionality involved.It is also noted that each block in the block diagrams and / or flowcharts and combinations of blocks in the block diagrams and / or flowcharts can be implemented by systems based on special hardware that performs the specified functions or effects, or combinations of special hardware and computer instructions.

[0165] The descriptions of the various embodiments of the present invention are provided for illustrative purposes; however, they are not intended to be exhaustive or limiting for the disclosed embodiments. Many modifications and variations will be obvious to a person skilled in the art without deviating from the scope and inventive concept of the described embodiments. The terminology used here has been chosen to best explain the basic ideas of the embodiments, their practical application, or technical improvements over technologies available on the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

[1] System for addressing and reading qubits, wherein the system comprises: a first lossless microwave switch connected to a quantum system; a second lossless microwave switch that can be connected to the first lossless microwave switch; and a quantum-limited amplifier that can be connected to the second lossless microwave switch. [2] System according to claim 1, further comprising a circulator configured to connect the first lossless microwave switch to the second lossless microwave switch. [3] System according to claim 2, wherein the circulator is configured to connect an input to the first lossless microwave switch. [4] System according to claim 1, wherein the second lossless microwave switch is configured to choose between connecting to the quantum-limited amplifier and connecting to a load dump. [5] System according to claim 1, wherein the quantum system comprises a first qubit connected at a first terminal to a first readout resonator, a second qubit connected at a second terminal to a second readout resonator, up to a last qubit connected at a last terminal to a last readout resonator, wherein each of the first to last qubits has a first to last qubit frequency. [6] System for addressing and reading qubits, wherein the system comprises: a first lossless microwave switch connected to a quantum system, wherein a first input is connectable to the first lossless microwave switch and a quantum-limited amplifier is connectable to the first lossless microwave switch; and a second lossless microwave switch connected to the quantum system, wherein a second input can be connected to the second lossless microwave switch, wherein the second input is configured to control the quantum system and the first input is configured to read out the quantum system. [7] System according to claim 6, further comprising a first circulator configured to connect the first input to the first lossless microwave switch and configured to connect the quantum-limited amplifier to the first lossless microwave switch. [8] System according to claim 7, wherein a second circulator is configured to connect the second input to the second lossless microwave switch and to connect a load dump to the second lossless microwave switch. [9] System according to claim 6, wherein the quantum system comprises a first qubit connected at a first terminal to a first readout resonator, a second qubit connected at a second terminal to a second readout resonator, up to a last qubit connected at a last terminal to a last readout resonator, wherein each of the first to last qubits has a first to last qubit frequency. [10] System according to claim 9, wherein the first to last qubit are controlled via the second lossless microwave switch; and wherein the first to last readout resonator are read out via the first lossless microwave switch. [11] System for addressing and reading qubits, wherein the system comprises: a lossless microwave signal distributor connected to a quantum system, wherein a first input is connectable to the lossless microwave signal distributor; and a lossless microwave switch connected to the quantum system, wherein a second input can be connected to the lossless microwave switch, wherein the second input is configured to control the quantum system via the lossless microwave switch and the first input is configured to read the quantum system via the lossless microwave signal distributor. [12] System according to claim 11, further comprising a first circulator configured to connect the first input to the lossless microwave signal distributor and configured to connect a quantum-limited amplifier to the lossless microwave signal distributor. [13] System according to claim 12, wherein a second circulator is configured to connect the second input to the lossless microwave switch and to connect a load dump to the lossless microwave switch. [14] System according to claim 11, wherein the quantum system includes a first qubit connected at a first terminal to a first readout resonator, a second qubit connected at a second terminal to a second readout resonator, up to a last qubit connected at a last terminal to a last readout resonator, each qubit having a first to last qubit frequency from the first to the last qubit. [15] System according to claim 14, wherein the first to last qubit are controlled via the lossless microwave switch; and wherein the first to last readout resonator are read out via the lossless microwave signal distributor. [16] System for addressing and reading qubits, wherein the system comprises: a lossless microwave signal distributor connected to a quantum system, wherein a first input is connected to the lossless microwave signal distributor; a lossless microwave switch connected to the quantum system, wherein a second input can be connected to the lossless microwave switch, the second input being configured to control the quantum system via the lossless microwave switch; and a lossless microwave signal combiner connected to the quantum system, wherein the first input is configured to read out the quantum system via the lossless microwave signal distributor and the lossless microwave signal combiner. [17] System according to claim 16, further comprising a quantum-limited amplifier connected to the lossless microwave signal combiner. [18] System according to claim 16, wherein a circulator is configured to connect the second input to the lossless microwave switch and to connect a load dump to the lossless microwave switch. [19] System according to claim 16, wherein the quantum system includes a first qubit connected at a first terminal to a first readout resonator, a second qubit connected at a second terminal to a second readout resonator, up to a last qubit connected at a last terminal to a last readout resonator, wherein each of the first to last qubits has a first to last qubit frequency. [20] System according to claim 19, wherein the first to last qubit are controlled via the lossless microwave switch; and wherein each of the first to last readout resonators is read out simultaneously via the lossless microwave signal distributor and the lossless microwave signal combiner.

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