Reading system, device and chip for amplifying signal, and application and method thereof

Abstract

This application discloses a reading system, a device and chip for signal amplification, and their applications and methods, all pertaining to the field of quantum bit measurement and control. The amplifier device comprises a primary transmissive impedance conversion line, a secondary transmissive impedance conversion line, and a parallel circuit formed by connecting multiple subcircuits therebetween. A capacitor is provided between each conversion line and the parallel circuit. The subcircuits comprise multiple ring loops based on a single Josephson junction, connected in series. This amplifier device can effectively amplify signals while providing improved saturation power.

Description

Technical Field

[0001] The present application belongs to the field of quantum information, especially the field of quantum bit measurement and control. In particular, the present application relates to a reading system, a device and chip for amplifying signals, and their applications and methods. Background Art

[0002] In a quantum computing system, in order to obtain the calculation results of the quantum chip, it is necessary to collect and analyze the signal output by the quantum chip, namely the quantum bit reading signal.

[0003] Qubit readout signals are typically very weak, so multiple amplifiers are typically required in the qubit readout signal output circuit to boost signal strength. However, currently used amplifiers are relatively large, significantly increasing the limited cooling space available in superconducting quantum computing systems, such as dilution refrigerators. Summary of the Invention

[0004] The examples of this application provide a reading system, a device and chip for signal amplification, and their applications and methods. This solution can be integrated into a substrate to provide a device with amplification functions in a single chip, effectively reducing its own space usage and thus reserving more cooling space for other devices and components in the superconducting quantum system that require cooling.

[0005] The solution of this application example is implemented through the following content.

[0006] In a first aspect, some examples of the present application provide an amplifier device.

[0007] It includes:

[0008] A primary transmissive impedance conversion line having a first input end and a first output end;

[0009] A secondary transmissive impedance conversion line having a second input end and a second output end;

[0010] a first capacitor having one end connected to the second input terminal and the other end grounded;

[0011] a second capacitor having one end connected to the first output terminal and the other end connected to ground; and

[0012] A parallel circuit connected between the first output terminal and the second input terminal and formed by connecting a plurality of sub-circuits in parallel;

[0013] The subcircuit has a plurality of ring loops connected in series, wherein the ring loops are formed by ring connecting lines and interrupted by a Josephson junction, and adjacent ring loops share a portion of the ring connecting line.

[0014] According to some examples of the present application, the primary transmissive impedance transformation line and the secondary transmissive impedance transformation line are the same device;

[0015] and / or, the first capacitor and the second capacitor are flat plate capacitors;

[0016] And / or, the primary transmissive impedance transformation line and the secondary transmissive impedance transformation line are each independently selected from a transmissive resonant cavity, optionally, the transmissive resonant cavity includes a quarter-wavelength resonator, or the transmissive resonant cavity includes a half-wavelength resonator and a quarter-wavelength resonator.

[0017] According to some examples of the present application, the number of sub-circuits in the parallel circuit is two;

[0018] and / or, each sub-circuit has an independent number of ring loops;

[0019] And / or, at least one subcircuit has five ring loops.

[0020] In a second aspect, some examples of the present application provide an amplifier device.

[0021] The amplifier device defines a signal flow path and includes:

[0022] A primary transmissive impedance conversion line having a first input end and a first output end;

[0023] A secondary transmissive impedance conversion line having a second input end and a second output end; and

[0024] a Josephson parametric amplifier connected between the first output port and the second input port;

[0025] The Josephson parametric amplifier includes: a first capacitor and a junction loop connected in parallel, the junction loop includes a plurality of radio frequency superconducting quantum interference devices connected in series, the plurality of radio frequency superconducting quantum interference devices are distributed along a signal flow path, one end of the first capacitor is connected to a first output end, and the other end is grounded;

[0026] The amplifier device further includes a second capacitor configured in pair with the first capacitor for providing signal loop symmetry. One end of the second capacitor is connected to the second input terminal, and the other end is grounded.

[0027] According to some examples of the present application, the junction loop includes: a first subcircuit and a second subcircuit connected in parallel to the signal flow path, wherein the first subcircuit and the second subcircuit are each composed of an independently selected number of radio frequency superconducting quantum interference devices connected in series.

[0028] According to some examples of the present application, the first sub-circuit and the second sub-circuit are identical, and each has five radio frequency superconducting quantum interference devices;

[0029] Each radio frequency superconducting quantum interference device includes a Josephson junction and a strip conductor, wherein two ends of the strip conductor are conductively connected to two superconductor electrodes of the Josephson junction respectively;

[0030] Optionally, the ribbon conductor includes a first conductor trace, a second conductor trace, and a third conductor trace electrically connected in sequence;

[0031] The first and third conductor traces are arranged parallel to each other along a first direction and spaced apart by a distance defined by the length of the second conductor trace, which is arranged along a second direction that is crisscrossed with the first direction.

[0032] In a third aspect, some examples of the present application disclose an amplifier chip, comprising:

[0033] and an amplifier circuit integrated into the substrate, wherein at least part of the amplifier circuit is provided by the aforementioned amplifier device of claim 1.

[0034] In a fourth aspect, some examples of the present application disclose a reading system for operating quantum bits, having the aforementioned amplifier device, or amplifier chip.

[0035] In a fifth aspect, some examples of the present application disclose the application of an amplifier device or an amplifier chip in a read operation process of a superconducting quantum bit.

[0036] Applications thereof include: amplifying a read output signal; or, applications include: serving as a pre-stage of a low noise amplifier to amplify a read output signal.

[0037] In a sixth aspect, some examples of the present application disclose a method for amplifying a signal, the method comprising:

[0038] Obtain an amplifier device, or amplifier chip;

[0039] A flux bias signal is applied based on global regulation to control the parallel circuit or the Josephson parametric amplifier, and the signal to be amplified and the pump signal are input from the first input end, so as to obtain the amplified target signal from the second output end.

[0040] Beneficial effects:

[0041] Current devices used to amplify the readout signals of superconducting qubits typically employ multiple independent devices connected by signal links, which function as a whole to amplify the signal. However, these devices are often large, which consumes the limited cooling resources of the dilution refrigerators in superconducting quantum computing systems, including cooling power and internal cooling space. This, in turn, limits the configuration of devices, such as quantum chips, and their various signal lines, that can perform quantum computing within them.

[0042] To address this issue, the exemplary solution of this application configures an amplifier based on circuit components such as transmissive impedance transformation lines, capacitors, and Josephson junctions. More importantly, these components can be constructed and implemented in a more miniaturized manner, allowing them to be integrated on existing substrates. This significantly reduces the size of the amplifier.

[0043] In addition, by combining a single Josephson junction with a ring circuit to form a radio frequency superconducting quantum interference device and connecting multiple of them in series, constructing the nonlinear inductance part of the amplifier can help improve the saturation power of the amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] For a clearer explanation, the following briefly introduces the drawings required for the description.

[0045] Figure 1 Schematic diagram of the structure of the Josephson parametric amplifier in the example of this application;

[0046] Figure 2 This is a schematic diagram of the structure of the amplifier chip in the example of this application;

[0047] Figure 3 A block diagram of the signal flow principle when amplifying a signal based on the amplifier in the example of this application;

[0048] Figure 4 A schematic diagram showing the coordination relationship between the pump signal and the input signal at the input end, and the output signal at the output end of the amplifier chip in the example of this application is shown.

[0049] Explanation of reference numerals: 100 - Josephson parametric amplifier; 101 - first capacitor; 103 - first sub-circuit; 104 - second sub-circuit; 200 - amplifier chip; 201 - second capacitor. DETAILED DESCRIPTION

[0050] Superconducting qubits require an extremely low temperature environment to perform quantum computing. In the industry, a device that provides this temperature environment is, for example, a dilution refrigerator. Qubits are placed in a dilution refrigerator to maintain the required extremely low temperature during quantum computing. The dilution refrigerator can also accommodate various other appropriate circuit components and circuits.

[0051] A dilution refrigerator has multiple temperature layers, each decreasing in temperature from top to bottom. The qubit or quantum chip can be located in the lowest temperature layer. The circuitry used to read and control the bits can start at room temperature, traverse each temperature layer, and finally reach the same layer as the quantum chip, where it connects. Furthermore, given that qubits are highly susceptible to various noises, such as thermal and electromagnetic noise, each circuit can be connected to various components to achieve specific purposes. For example, filters, amplifiers, circulators, and attenuators can be used.

[0052] In some examples, a copper powder filter, a high electron mobility transistor (HEMT), etc. may be configured.

[0053] It is known that these discrete devices have a relatively large space occupation, which will limit the configuration of more bits, because more bits mean that more related devices need to be introduced.

[0054] Therefore, it would be extremely advantageous if a collection of various devices could be designed and implemented that could be integrated into a single chip to form an on-chip amplifier.

[0055] In some attempts, the applicants have chosen to use impedance-matched quantum parametric amplifiers (IMAPs). These typically use a superconducting quantum interference device (SQID) with a double-junction (Josephson junction) to establish nonlinear transmission, thereby achieving relatively large gain and bandwidth. However, these IMAPs have low saturation power and are unable to amplify large signals. In other words, such amplifiers are difficult to meet the high saturation power requirements.

[0056] Based on this reality, in an example of this application, a new amplifier is proposed, which has the potential to provide high saturation power while occupying a smaller space.

[0057] A major improvement of the solution proposed in the example of this application is that it eliminates the use of a double-junction superconducting quantum interference device (also described as a DC superconducting quantum interference device) and simultaneously uses a superconducting quantum interference device with a single junction (also described as a radio frequency superconducting quantum interference device). This is mainly achieved by connecting multiple such single-junction superconducting quantum interference devices using inductive (inductive characteristics, which can provide linear inductance; in contrast, a Josephson junction can behave as a nonlinear inductor) connecting wires. The new structure formed in this way can provide higher saturation power.

[0058] The following will be combined with this application example to explain the solution in more detail. Please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 .

[0059] In some examples, the amplifier device includes a primary transmissive impedance transformation line, a secondary transmissive impedance transformation line, a first capacitor 101 , a second capacitor 201 , and a parallel circuit.

[0060] The primary transmissive impedance transformation line has a first input terminal and a first output terminal; the secondary transmissive impedance transformation line has a second input terminal and a second output terminal. Under this definition, one end of the first capacitor 101 is connected to the second input terminal, and the other end of the first capacitor 101 is grounded. One end of the second capacitor 201 is connected to the first output terminal, and the other end of the second capacitor 201 is grounded. A parallel circuit is connected between the first output terminal and the second input terminal. The parallel circuit is formed by connecting multiple sub-circuits in parallel.

[0061] In addition, one or more sub-circuits constituting the parallel circuit have multiple ring loops connected in series. In different examples, the number of sub-circuits in the parallel circuit can be configured to different numbers, such as at least two, according to the purpose and requirements (e.g., in combination with the resonant frequency of the Josephson parametric amplifier 100 in the amplifier).

[0062] The loops are formed by inductively connected conductors (inductive connecting lines; or simply described as inductors) that provide parasitic inductance to be taken into account when calculating the Josephson junction frequency, and are interrupted by a Josephson junction. Therefore, for a single subcircuit, the number of loops therein can also be configured as needed (for example, taking into account the introduced parasitic inductance) and is not particularly limited. In some cases, each subcircuit in a parallel circuit has an independent number of loops. Therefore, the number of loops in each subcircuit can be equal or different, for example, the number of loops in some subcircuits is the same, while the number of loops in other subcircuits is different. Exemplarily, at least one subcircuit has five loops. In a more specific and alternative example, as shown in the illustrated scheme, the parallel circuit has two subcircuits, and both have an equal number (five in the illustration) of loops.

[0063] As mentioned above, the loop is interrupted by a Josephson junction. Therefore, it can be understood that the two ends of the inductor, an example of a loop, are respectively connected to the two electrodes (upper and lower electrodes, or top and bottom electrodes, or two superconducting layers) of the Josephson junction (JJ). Taking the aluminum-aluminum oxide-aluminum Josephson junction as an example, the two electrodes refer to two aluminum electrodes. In the multiple loops of each subcircuit, adjacent loops also share portions of the inductor.

[0064] In the above example, based on process convenience, the primary and secondary transmissive impedance transformation lines can be identical devices. Of course, in other examples, if necessary, they can be implemented as different devices. These differences can include the same shape but different structural dimensions, or differences in both shape and dimensions.

[0065] In some specific and alternative examples, the primary transmissive impedance transformation line and the secondary transmissive impedance transformation line can each be independently selected as a transmissive resonant cavity. The transmissive resonant cavity can be, for example, a single type of resonator, such as a quarter-wavelength resonator; or a combination of multiple types of resonators, such as two types, such as a half-wavelength resonator and a quarter-wavelength resonator.

[0066] The first capacitor 101 and the second capacitor 201 in the amplifier device can be constructed as parallel plate capacitors. To facilitate integration in a single chip, two metal films, metal wires, metal strips, or metal plates of a certain size can be formed on the surface of the chip substrate by deposition, for example, to serve as the two electrodes of the parallel plate capacitor. The material used is, for example, aluminum.

[0067] In some other examples, the present application further discloses an amplifier device. In order to facilitate the description and definition of other components therein, a main signal flow path in the amplifier device is defined.

[0068] The amplifier device includes a primary transmissive impedance transformation line having a first input terminal and a first output terminal, a secondary transmissive impedance transformation line having a second input terminal and a second output terminal, and a Josephson parametric amplifier 100 connected between the first output port and the second input port. Based on this, the signal flow path can be roughly described as from the first input terminal (signal input) of the primary transmissive impedance transformation line to the second output terminal (signal output) of the secondary transmissive impedance transformation line.

[0069] In some selectively constructed examples, the Josephson parametric amplifier 100 can be functionally embodied by the aforementioned parallel circuit. This Josephson parametric amplifier 100 includes a first capacitor 101 and a junction loop. The first capacitor 101 and the junction loop are configured in parallel; one end of the first capacitor 101 is connected to the first output terminal, and the other end is grounded; the junction loop is distributed along the signal flow path. It will be understood that the first capacitor 101 and the junction loop have two end nodes, and these two end nodes serve as the two common endpoints of the parallel circuit, forward and backward in the signal flow, and are therefore connected to the signal flow path.

[0070] As the name suggests, a knot loop is a loop with a Josephson junction (JJ). In this example, the knot loop is primarily implemented by connecting a number of radio frequency superconducting quantum interference devices in series. Therefore, the knot loop includes multiple RF superconducting quantum interference devices connected in series; these RF superconducting quantum interference devices are distributed along the signal flow path. That is, the RF superconducting quantum interference devices in the knot loop are arranged one by one in sequence along the signal flow path.

[0071] In addition, the amplifier device further includes a second capacitor 201 configured in pair with the first capacitor 101. The second capacitor 201 is used to provide symmetry in the signal loop. One end of the second capacitor 201 is connected to the second input end of the secondary transmissive impedance conversion line, and the other end of the second capacitor 201 is grounded.

[0072] In this example, first capacitor 101 and second capacitor 201 can be constructed as parallel plate capacitors, as described above. That is, each of the two capacitors has two capacitive plates. If necessary, first capacitor 101 and second capacitor 201 can also be constructed as a single conductive plate, acting as a device providing capacitance in the form of capacitance to ground.

[0073] As an example, the knot-containing loop may include: a first subcircuit 103 and a second subcircuit 104 connected in parallel to the signal flow path. Wherein, the first subcircuit 103 and the second subcircuit 104 both rely on the construction of a radio frequency superconducting quantum interference device. In the two subcircuits, the number of radio frequency superconducting quantum interference devices is plural and combined in series; the number of radio frequency superconducting quantum interference devices possessed by the two is independent, so the two have a number of radio frequency superconducting quantum interference devices selected independently. In some optional specific examples, the first subcircuit 103 and the second subcircuit 104 are the same (for example, manufactured with the same process, structural design and size), and each has five radio frequency superconducting quantum interference devices.

[0074] The radio frequency superconducting quantum interference device is a circuit with a single Josephson junction. In the example, the radio frequency superconducting quantum interference device includes a strip conductor and a Josephson junction. The two ends of the strip conductor are conductively connected to the two superconductor electrodes of the Josephson junction respectively. The strip conductor mainly includes a three-terminal conductor (although it is described as a wire, it can be realized in the process of metal such as aluminum strips). The three-terminal conductor is, for example, a first conductor trace, a second conductor trace and a third conductor trace that are electrically connected in sequence. The conductor trace can be formed of a superconducting material that exhibits superconducting properties at a temperature equal to or lower than the critical temperature, for example, at about 10-100 millikelvin (mK) or about 4K. The superconducting material is, for example, aluminum, niobium, tantalum or titanium nitride, etc.; in specific implementation, it is not limited to these materials, and any material that exhibits superconducting properties at a temperature equal to or lower than the critical temperature can be used to form the superconducting transmission line.

[0075] The first conductor trace, the second conductor trace, and the third conductor trace can have various suitable arrangements or routing patterns. In an optional example, the three traces are selectively distributed in two directions—a first direction and a second direction. The second direction can be consistent with the main signal flow direction in the amplifier device, and the first direction is interlaced with the second direction. That is, the first direction and the second direction are arranged vertically and horizontally. On this basis, the first conductor trace and the third conductor trace (L1) are arranged parallel to each other along the first direction. The first conductor trace and the third conductor trace are separated from each other by a distance defined by the length of the second conductor trace (L2). The second conductor trace is arranged along a second direction that intersects the first direction. Therefore, the strip conductor formed by the first conductor trace, the second conductor trace, and the third conductor trace, when connected to a Josephson junction, can form a roughly quadrilateral shape, or a shape similar to a rectangle.

[0076] Furthermore, for a subcircuit having multiple RF superconducting quantum interference devices, these RF superconducting quantum interference devices are selectively configured so that the Josephson junctions in two adjacent RF superconducting quantum interference devices are not on the same side. For example, as described above, a single RF superconducting quantum interference device presents a rectangle composed of a Josephson junction and strip conductors connected to both ends of the junction. In two adjacent rectangles (RF superconducting quantum interference devices), the Josephson junctions of the two are not on the same side of the rectangle. Moreover, if only the individual strip conductors in the subcircuit are identified and considered as a whole, it can be considered to have an S-curve structure.

[0077] For ease of use, the above amplifier device may be integrated, for example, integrated and packaged to form an amplifier chip 200. Therefore, in some examples, an amplifier chip 200 is proposed, which includes a substrate, an amplifying circuit integrated into the substrate, and a substrate.

[0078] The amplifier circuitry is at least or entirely provided by the aforementioned amplifier device or its variations. Therefore, the amplifier circuitry in amplifier chip 200 can be similar in structure to that in the aforementioned amplifier device embodiment and have the same beneficial effects, and thus will not be described in detail here. For technical details not disclosed in this embodiment, those skilled in the art should refer to the above description for understanding, and to save space, they will not be detailed here.

[0079] The substrate of the amplifier chip 200 can be high-resistance silicon, sapphire or other materials. The manufacturing process of the amplifier circuit can refer to existing semiconductor integrated circuit processes, such as photolithography, etching, deposition and the like.

[0080] The various steps involved in the manufacture of semiconductor and / or superconducting devices and semiconductor / superconductor-based ICs are well known, and therefore, for the sake of brevity, many conventional steps will be mentioned only briefly or omitted entirely without providing well-known process details. That is, for the sake of brevity, conventional techniques associated with the manufacture of semiconductor and / or superconducting devices and integrated circuits (ICs) may be simplified or described. Furthermore, various tasks and process steps herein may be incorporated into more comprehensive procedures or processes having additional steps or functionality not described in detail herein.

[0081] As mentioned above, the amplifier device in the example and the product based on it (such as the amplifier chip 200) can be used to amplify signals, for example, to amplify the read output signal of a superconducting quantum bit. Therefore, a reading system for operating quantum bits can also be implemented based on the amplifier device and the chip. In order to further suppress noise, a low-noise amplifier can also be provided in the reading system at the rear stage of the amplifier device. Accordingly, the amplifier device / chip serves as the front stage of the low-noise amplifier. Therefore, the amplification process of the read output signal of the superconducting quantum bit can be first passed through the amplifier device in the example, and then passed through the low-noise amplifier.

[0082] Of course, in other scenarios where signal amplification is required, the amplifier in the example of this application may also be used, and is not limited to amplifying the read output signal of the superconducting quantum bit; the read output signal is a feedback signal generated by the bit in response to the input signal of the read operation.

[0083] The readout system includes an amplifier device or amplifier chip 200. Furthermore, it may include a signal source, such as a microwave source for input signals and a vector network analyzer for analyzing output signals. The readout system can be optionally integrated into the measurement and control system of a superconducting quantum computing system as a sub-functional module.

[0084] In the case of the aforementioned amplifier device / chip and its products, when they are used to amplify a signal, such as a read output signal of a superconducting quantum bit, a bias signal, a signal to be amplified, and a pump signal can be input to the amplifier, thereby obtaining a target signal through mixing and amplification.

[0085] Because different quantum chips or qubits can produce different readout and output signals, the amplifier can be controlled or adjusted to suit its operation. For example, the characteristic parameters of a single Josephson junction loop can be altered. This regulation can be achieved by applying a magnetic field, causing the loop's electrical properties to change due to changes in magnetic flux.

[0086] Because the amplifier comprises a parallel circuit, the Josephson parametric amplifier 100 device includes multiple Josephson junctions, and in combination with correspondingly configured capacitors, all of the junctions can be selectively controlled, thereby demonstrating global regulation using a flux bias signal (e.g., a magnetic field covering the entire amplifier chip 200). Based on this, the signal to be amplified and the pump signal are input from the first input port, and the amplified target signal is obtained from the second output port. The pump signal and the signal to be amplified / to be amplified can be combined using a combiner for input to the first input port.

[0087] In the above example, the amplifier of the present application can effectively amplify the signal while achieving better saturation power; since the pump signal is directly injected into the signal loop, the required driving energy is smaller, reducing energy loss.

[0088] Furthermore, the amplifier of the present application does not need to be configured with a circulator, thereby reducing the need to integrate the circulator into a single chip and also eliminating the equipment that provides the working conditions for the circulator.

[0089] Furthermore, when the amplifier is operating in its optimal mode, the pump signal frequency does not need to be a multiple of the signal frequency to be amplified. For example, the pump signal input frequency can be the center frequency of the desired amplification band. For example, if a signal between 7 GHz and 7.4 GHz is to be amplified, the corresponding pump signal frequency can be around 7.2 GHz.

[0090] The embodiments described above with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application.

[0091] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, one or more embodiments are described above with reference to the accompanying drawings. Wherein, similar reference numerals are used to refer to similar components throughout the text. In the above description, for the purpose of explanation, many specific details are set forth in order to provide a more thorough understanding of one or more embodiments. However, it is obvious that in various cases, one or more embodiments can be practiced without these specific details, and the various embodiments can be combined and referenced with each other without contradiction.

[0092] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0093] The above describes in detail the structure, features and effects of the present application based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present application, but the present application does not limit the scope of implementation to what is shown in the drawings. Any changes made in accordance with the concept of the present application, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the scope of protection of the present application.

Claims

1. An amplifier device, characterized in that: include: A primary transmissive impedance conversion line having a first input end and a first output end; A secondary transmissive impedance conversion line having a second input end and a second output end; a first capacitor having one end connected to the second input terminal and the other end grounded; a second capacitor having one end connected to the first output terminal and the other end grounded; as well as A parallel circuit connected between the first output terminal and the second input terminal and formed by connecting a plurality of sub-circuits in parallel; The subcircuit has a plurality of ring loops connected in series, wherein the ring loops are formed by ring connecting lines and interrupted by a Josephson junction, and adjacent ring loops share a portion of the ring connecting line.

2. The amplifier device according to claim 1, wherein The primary transmissive impedance transformation line and the secondary transmissive impedance transformation line are the same device; and / or, the first capacitor and the second capacitor are flat plate capacitors; And / or, the primary transmissive impedance transformation line and the secondary transmissive impedance transformation line are each independently selected from a transmissive resonant cavity.

3. The amplifier device according to claim 1, wherein The primary transmissive impedance transformation line and the secondary transmissive impedance transformation line are each independently selected from a transmissive resonant cavity, wherein the transmissive resonant cavity includes a quarter-wavelength resonator, or wherein the transmissive resonant cavity includes a half-wavelength resonator and a quarter-wavelength resonator.

4. The amplifier device according to claim 1, 2 or 3, characterized in that The number of sub-circuits in the parallel circuit is two; and / or, each sub-circuit has an independent number of ring loops; And / or, at least one subcircuit has five ring loops.

5. An amplifier device, characterized in that: Having a signal flow path defined therein, the amplifier device comprises: A primary transmissive impedance conversion line having a first input end and a first output end; A secondary transmissive impedance conversion line having a second input end and a second output end; and a Josephson parametric amplifier connected between the first output port and the second input port; The Josephson parametric amplifier includes: a first capacitor and a junction loop connected in parallel, the junction loop includes a plurality of radio frequency superconducting quantum interference devices connected in series, the plurality of radio frequency superconducting quantum interference devices are distributed along a signal flow path, one end of the first capacitor is connected to a first output end, and the other end is grounded; The amplifier device further includes a second capacitor configured in pair with the first capacitor for providing signal loop symmetry, wherein one end of the second capacitor is connected to the second input terminal and the other end is grounded.

6. The amplifier device according to claim 5, characterized in that The junction loop includes: a first subcircuit and a second subcircuit connected in parallel to the signal flow path, wherein the first subcircuit and the second subcircuit are each composed of a number of independently selected radio frequency superconducting quantum interference devices connected in series.

7. The amplifier device according to claim 6, characterized in that The first subcircuit and the second subcircuit are identical and each have five radio frequency superconducting quantum interference devices; Each radio frequency superconducting quantum interference device includes a Josephson junction and a strip conductor, and two ends of the strip conductor are conductively connected to two superconductor electrodes of the Josephson junction respectively.

8. The amplifier device according to claim 7, characterized in that The ribbon conductor includes a first conductor trace, a second conductor trace, and a third conductor trace that are electrically connected in sequence; The first and third conductor traces are arranged parallel to each other along a first direction and spaced apart by a distance defined by the length of the second conductor trace, which is arranged along a second direction that is crisscrossed with the first direction.

9. An amplifier chip, characterized in that include: substrate; as well as An amplifier circuit is integrated into the substrate, and at least part of the amplifier circuit is provided by the amplifier device according to any one of claims 1 to 8.

10. A reading system for operating quantum bits, characterized in that A device comprising the amplifier device according to any one of claims 1 to 8, or the amplifier chip according to claim 9.

11. Use of the amplifier device according to any one of claims 1 to 8, or the amplifier chip according to claim 9, in a read operation of a superconducting quantum bit.

12. The use according to claim 11, characterized in that The application includes amplifying a read output signal.

13. The use according to claim 11, characterized in that The applications include: serving as a pre-stage of a low noise amplifier to amplify a read output signal.

14. A method for amplifying a signal, characterized in that: The method comprises: Obtaining the amplifier device according to any one of claims 1 to 8, or the amplifier chip according to claim 9; A flux bias signal is applied based on global regulation to control the parallel circuit or the Josephson parametric amplifier, and a signal to be amplified and a pump signal are input from a first input end, thereby obtaining an amplified target signal from a second output end.

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