A superconducting quantum chip and a superconducting quantum computer

Abstract

The embodiment of the application provides a superconducting quantum chip and a superconducting quantum computer. In the application, the superconducting quantum chip comprises a transmission line, a control line and a quantum bit. The transmission line can comprise an input line. The input line is connected with the control line. The control line is electromagnetically coupled with the quantum bit. The input line is used for transmitting a first microwave signal sent by a microwave device to the control line. The control line is used for changing the state of the quantum bit based on the first microwave signal, so as to realize quantum computation. The difference between the impedance of the transmission line and the impedance of the microwave device is less than a preset value. The impedance of the transmission line is determined according to the dynamic inductance, the geometric inductance and the capacitance of the transmission line. The introduction of the dynamic inductance can increase the overall inductance of the transmission line, improve the impedance of the transmission line, and reduce the difference between the impedance of the transmission line and the impedance of the microwave device. When the transmission line is used as the input line, the reflection of the first microwave signal transmitted on the input line can be reduced, and the control accuracy of the quantum bit can be improved.

Description

Technical Field

[0001] This application relates to the field of quantum computing technology, and in particular to a superconducting quantum chip and a superconducting quantum computer. Background Technology

[0002] Quantum computing is a novel computing method that utilizes principles of quantum mechanics, such as the superposition and entanglement properties of qubits. Compared to classical computing, quantum computing theoretically offers exponential speedup advantages for certain specific problems, such as large number factorization and quantum chemical simulation.

[0003] On a superconducting quantum chip, multiple qubits are integrated together and controlled by microwave signals from a microwave device. Because microwave signals have very short wavelengths, they are reflected on the transmission line. The reflected microwave signal, superimposed on the original microwave signal, alters the original signal and thus affects the accuracy of qubit control. To improve the accuracy of qubit control, the reflected microwave signal needs to be reduced. However, the reflected microwave signal is affected by the impedance of the transmission line, and the closer the impedance of the transmission line is to the impedance of the microwave device, the smaller the reflected microwave signal. Therefore, increasing the impedance of the transmission line becomes crucial. Summary of the Invention

[0004] This application provides a superconducting quantum chip and a superconducting quantum computer to improve the impedance of the transmission lines on the superconducting quantum chip, thereby improving the accuracy of manipulating qubits.

[0005] Firstly, a superconducting quantum chip is provided. The superconducting quantum chip includes a transmission line, a control line, and qubits. The transmission line may include an input line, which can be directly connected to the control line. The control line and the qubits can be electromagnetically coupled, such as by capacitive coupling or inductive coupling. The input line is used to transmit a first microwave signal sent by a microwave device to the control line. The control line is used to change the state of the qubits based on the first microwave signal, thereby realizing quantum computing. The impedance difference between the transmission line and the impedance of the microwave device is less than a preset value, and the impedance of the transmission line is determined based on the dynamic inductance, geometric inductance, and capacitance of the transmission line.

[0006] Thus, the impedance of the transmission line depends simultaneously on its dynamic inductance, geometric inductance, and capacitance. Since the impedance is positively correlated with inductance, the introduction of dynamic inductance increases the overall inductance of the transmission line on top of its geometric inductance. Therefore, the impedance of the transmission line can be increased, reducing the difference between the transmission line's impedance and the impedance of the microwave device. Furthermore, using such a transmission line as an input line reduces the reflection of the first microwave signal transmitted on the input line, thereby improving the accuracy of quantum bit manipulation.

[0007] In one possible implementation, the superconducting quantum chip may further include a readout cavity, and the transmission line may further include an output line. Furthermore, the qubits may be electromagnetically coupled to the readout cavity (e.g., capacitive coupling, inductive coupling), and the readout cavity may be electromagnetically coupled to the output line (e.g., capacitive coupling, inductive coupling). The output line is used to transmit a second microwave signal sent by a microwave device to the readout cavity. The readout cavity is used to read the state of the qubits after quantum computation based on the second microwave signal and feed back the read state to the output line in the form of a microwave signal. The output line is also used to output the state of the qubits after quantum computation.

[0008] In other words, using such a transmission line as the output line can reduce the reflection of the second microwave signal, thereby improving the accuracy of reading the state of the quantum bit.

[0009] In one possible implementation, the picohenry (pH) of the transmission line fabrication material is greater than or equal to 50 picohenries and less than or equal to 3000 pH. Here, picohenry refers to the dynamic inductance along the length of a cuboid made of this material, with a thickness of 1 nanometer (nm) and equal length and width. In practical applications, picohenry can be expressed as pH·nm / square, where square indicates equal length and width. For example, if the picohenry of a certain material is 50 pH·nm / square, it means that the dynamic inductance along the length of a 1 nm thick cuboid made of this material with equal length and width is 50 pH.

[0010] Since the box dynamic inductance of most conductive materials with dynamic inductance is between 50 pH·nm / square and 3000 pH·nm / square, it is easy to select conductive materials for transmission lines within this range. The wider selection of conductive materials also provides more possibilities for the subsequent selection of transmission line size.

[0011] In one possible implementation, the width of the transmission line is greater than or equal to 2 micrometers (um) and less than or equal to 4 um.

[0012] Since transmission lines with a width of 2µm to 4µm are relatively easy to fabricate, choosing this range can reduce the difficulty of fabricating transmission lines and improve the yield rate.

[0013] In one possible implementation, the superconducting quantum chip further includes a wiring layer for arranging transmission lines, and when the dielectric material in the wiring layer is silicon nitride, the thickness of the transmission lines is greater than or equal to 0.3 nm and less than or equal to 4000 nm.

[0014] When silicon nitride is used as the dielectric material in the wiring layer, transmission lines with a thickness of 0.3 nm to 4000 nm are achievable with current micro-nano fabrication technology, thus ensuring the yield of transmission lines.

[0015] In one possible implementation, the superconducting quantum chip further includes a wiring layer for arranging transmission lines, and when the dielectric material in the wiring layer is silicon oxide, the thickness of the transmission lines is greater than or equal to 0.8 nm and less than or equal to 6000 nm.

[0016] When silicon oxide is used as the dielectric material in the wiring layer, transmission lines with a thickness of 0.8 nm to 6000 nm are achievable with current micro-nano fabrication processes, thus ensuring the yield rate of the transmission lines.

[0017] In one possible implementation, the transmission line is made of one or more of the following materials: titanium nitride (TiN), niobium nitride (NbN), aluminum nitride (AlN), tantalum nitride (TaN), niobium titanium nitrogen (NbTiN), granular aluminum, niobium silicon (NbSi), and titanium aluminum nitrogen (TiAlN).

[0018] Since these materials are all high dynamic inductance materials (meaning the material's square dynamic inductance is greater than a given value, such as 50 pH·nm / square), it is easier to fabricate transmission lines with high dynamic inductance using these materials. Since the impedance of a transmission line is positively correlated with its dynamic inductance, it is also easier to improve the impedance of the transmission line using these materials.

[0019] In one possible implementation, the impedance of the microwave device may be 50 ohms (Ω).

[0020] The target impedance of transmission lines can be the current industry standard of 50Ω. With future development, the industry standard may be raised to 55Ω, 60Ω, 65Ω, 70Ω, etc., and the impedance of microwave equipment may also change with the industry standard, such as being raised to 55Ω, 60Ω, 65Ω, 70Ω, etc.

[0021] In one possible implementation, the impedance of the transmission line is greater than or equal to 30Ω.

[0022] In other words, when the impedance of the microwave device is 50Ω, the impedance of the transmission line can be any value between 30Ω and 50Ω. Furthermore, the closer the impedance of the transmission line is to 50Ω, the higher the impedance matching degree with the microwave device.

[0023] Secondly, a superconducting quantum computer is provided, comprising a control and measurement device, any of the aforementioned superconducting quantum chips, and a dilution refrigerator. The control and measurement device is used to control microwave equipment to send microwave signals to the superconducting quantum chip, the superconducting quantum chip is used to perform quantum computing based on the microwave signals, and the dilution refrigerator is used to provide the ambient temperature required for quantum computing by the superconducting quantum chip.

[0024] For the technical effects that can be achieved in the second aspect mentioned above, please refer to the description of the technical effects that can be achieved by the corresponding design scheme in the first aspect mentioned above. This application will not repeat the description here. Attached Figure Description

[0025] Figure 1 An equivalent circuit for a unit length transmission line provided in this application;

[0026] Figure 2 A schematic diagram of a cuboid dynamic inductor made of superconducting material provided for an embodiment of this application;

[0027] Figure 3 A circuit provided in this application;

[0028] Figure 4 A schematic diagram of a superconducting quantum computer provided for an embodiment of this application;

[0029] Figure 5 This is a schematic diagram of the structure of a superconducting quantum chip provided in an embodiment of this application;

[0030] Figure 6a A schematic diagram illustrating a reflective readout of the state of a quantum bit, provided as an embodiment of this application;

[0031] Figure 6b A schematic diagram illustrating a suspended readout of the state of a quantum bit, provided as an embodiment of this application;

[0032] Figure 7 This is a schematic diagram of the internal connections of a superconducting quantum chip provided in an embodiment of this application;

[0033] Figure 8 This is a schematic diagram of the structure of another superconducting quantum chip provided in the embodiments of this application;

[0034] Figure 9 This is a schematic diagram of a wiring layer provided in an embodiment of this application;

[0035] Figure 10 A schematic diagram of the distribution of a transmission line provided in an embodiment of this application;

[0036] Figure 11 This is another schematic diagram of the distribution of a transmission line provided in an embodiment of this application;

[0037] Figure 12 A simulation diagram illustrating the relationship between the impedance of a transmission line and the thickness of silicon nitride during impedance matching, provided for an embodiment of this application;

[0038] Figure 13 A schematic diagram illustrating the relationship between the dynamic inductance of a transmission line and the thickness of silicon nitride, provided for an embodiment of this application;

[0039] Figures 14a to 14e A schematic diagram illustrating the relationship between the thickness of silicon nitride and the thickness of the transmission line during impedance matching, as provided in an embodiment of this application.

[0040] Figure 15 A schematic diagram illustrating the relationship between the dynamic inductance of a transmission line and the thickness of silicon oxide, provided for an embodiment of this application;

[0041] Figures 16a to 16e This is a schematic diagram showing the relationship between the thickness of silicon oxide and the thickness of the transmission line during impedance matching, as provided in an embodiment of this application. Detailed Implementation

[0042] Before introducing a superconducting quantum chip and a superconducting quantum computer provided in the embodiments of this application, some concepts involved in this application will be explained.

[0043] (1) Quantum bit.

[0044] A qubit is the fundamental unit in quantum computing, similar to an information bit in classical computing. However, while an information bit has only two states, 0 and 1, a qubit can exist not only in 0 and 1, but also in a superposition of 0 and 1. This superposition allows superconducting quantum computers to explore multiple solutions to a problem simultaneously, something classical computers cannot do. This property makes superconducting quantum computers suitable for solving problems that can be significantly accelerated through parallel processing, such as factorization and large-scale search.

[0045] (2) Geometric inductance.

[0046] Geometric inductance refers to the inductance determined by the physical shape of a transmission line. It characterizes the transmission line's ability to store magnetic field energy and is related to the transmission line's length, width, thickness, and arrangement.

[0047] (3) Impedance.

[0048] In a circuit with resistance, inductance, and capacitance, the opposition to the flow of current in the circuit is called impedance.

[0049] In practical applications, the equivalent circuit of a transmission line per unit length can be as follows: Figure 1 As shown, R, L, G, and C represent the resistance, geometric inductance, conductance, and capacitance of the transmission line, respectively. Figure 1 The impedance of the circuit shown, i.e., the impedance of the transmission line, is:

[0050]

[0051] The transmission line in this application is a lossless transmission line, meaning that R and G in the above formula are zero. Therefore, the impedance of the transmission line is:

[0052]

[0053] (4) Dynamic inductance.

[0054] Dynamic inductance is a unique phenomenon exhibited by superconducting materials such as titanium nitride, niobium nitride, aluminum nitride, tantalum nitride, niobium titanium nitride, particulate aluminum, niobium silicon, and titanium aluminum nitride. This phenomenon originates from the mass effect of charge carriers (such as Cooper pairs or quasi-particles). Unlike traditional geometric inductance, dynamic inductance directly depends on the dynamic properties of charge carriers within the material. When current flows through a superconducting material, the acceleration and deceleration of charge carriers lead to additional inductance effects, i.e., dynamic inductance.

[0055] (5) Square dynamic inductance.

[0056] See Figure 2 , Figure 2 This diagram illustrates a dynamic inductor in a cuboid made of superconducting material, as provided in an embodiment of this application. In the diagram, W represents the width of the cuboid, L represents its length, and T represents its thickness, with W and L being equal. In practical applications, the cuboid will generate inductance in both its length and thickness directions, as indicated by the arrows. The dynamic inductance of the cuboid refers to the inductance in the length direction when T = 1 nm. Furthermore, regardless of the side length of the cuboid, the inductance generated in the length direction when T = 1 nm is the same.

[0057] Generally, the dynamic inductance of superconducting materials is:

[0058]

[0059] in, Let be the reduced Planck constant, be the resistivity of the superconducting material in its normal state, Δ(T) be the superconducting band gap of the superconducting material, and t be the thickness of the superconducting material. When t = 1 nm, the value of 'a' is the block dynamic inductance of the superconducting material.

[0060] (6) Sheet resistance.

[0061] Sheet resistance, also known as sheet resistance or surface resistivity, refers to the resistance of a square thin film made of conductive material. A key characteristic of sheet resistance is that the sheet resistance remains constant regardless of the side length of the square.

[0062] (7) Impedance matching.

[0063] See Figure 3 ,exist Figure 3 In the circuit shown, the voltage of the signal source is Internal impedance of the signal source load impedance Where r represents the real part impedance of the signal source, X r R represents the imaginary impedance of the signal source, and R represents the real impedance of the load. R This represents the imaginary impedance of the load.

[0064] Therefore, the current is:

[0065]

[0066] The effective value of the current is:

[0067] Among them, U rms Indicates the effective value of the signal source voltage.

[0068] The load power is:

[0069]

[0070] Therefore, when Z R =Z r That is, R = r, X R =-X r At that time, the load power is at its maximum.

[0071] When the impedances of the signal source and the load are matched (i.e., the real parts of the impedances of the signal source and the load are equal and the imaginary parts are opposite), the load can obtain the maximum output power. This is called impedance matching.

[0072] To maximize the power delivered to the load, the impedances of the signal source and the load should be conjugate matched. In high-frequency circuit design practice, more attention is paid to selecting a standardized real impedance value and handling the imaginary part through other means (such as matching networks) to achieve optimal overall performance and compatibility. Therefore, it is sufficient to design the real impedance value to a standardized real impedance value.

[0073] In superconducting quantum chips, the signal source is a microwave device such as a microwave source or an arbitrary waveform generator. The quantum computing of a superconducting quantum chip is controlled by the microwave signal emitted by this device. Because the wavelength of the microwave signal is very short, it is reflected on the transmission line. The reflected microwave signal, superimposed on the original microwave signal, alters the original signal, thus affecting the accuracy of quantum bit manipulation. To minimize microwave signal reflection on the transmission line and improve the accuracy of quantum bit manipulation, the impedance of the transmission line needs to be increased.

[0074] To improve the impedance of transmission lines in superconducting quantum chips, this application embodiment uses superconducting materials to fabricate transmission lines, giving them dynamic inductance. Dynamic inductance can increase the overall inductance of the transmission line on top of geometric inductance. Since the impedance of the transmission line is positively correlated with the overall inductance, the impedance of the transmission line can be improved, thus reducing the difference between the impedance of the transmission line and the impedance of the microwave device.

[0075] The superconducting quantum chip in this application embodiment is mainly used in superconducting quantum computers. In order to better introduce the superconducting quantum chip, the superconducting quantum computer will be introduced first below.

[0076] See Figure 4 , Figure 4 This schematic diagram illustrates a superconducting quantum computer 100 provided in an embodiment of this application, including a dilution refrigerator 110, a measurement and control device 120, and a superconducting quantum chip 130. The superconducting quantum chip 130 is located at the bottom of the dilution refrigerator 110 and is placed within a protective cavity to isolate it from external interference. The superconducting quantum chip 130 operates at an ambient temperature close to absolute zero (minus 273.15 degrees Celsius). The measurement and control device 120 and the superconducting quantum chip 130 are connected by a cable. The measurement and control device 120 may include a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. The measurement and control device 120 may also include hardware chips such as application-specific integrated circuits (ASICs) and programmable logic devices (PLDs). Furthermore, the PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), or a generic array logic (GAL).

[0077] The dilution refrigerator 110 is used to provide the superconducting quantum chip 130 with the ambient temperature required for quantum computing, such as -273.15 degrees Celsius. Generally, the temperature inside the dilution refrigerator 110 gradually decreases from top to bottom, with the temperature at the bottom reaching the ambient temperature required for the superconducting quantum chip 130 to perform calculations.

[0078] The measurement and control equipment 120 is used to control the modulation pulse signals of microwave equipment, digital-to-analog converter (DAC) and other devices according to the needs of quantum computing tasks, generate a series of microwave manipulation pulse sequences, and input the microwave manipulation pulse sequences to the superconducting quantum chip 130 through a cable to control the state of the qubits on the superconducting quantum chip 130.

[0079] The superconducting quantum chip 130 is used for quantum computing based on microwave-manipulated pulse sequences.

[0080] The measurement and control equipment 120 is also used to control the microwave equipment to output microwave measurement pulse signals to the superconducting quantum chip 130 after the quantum computing is completed. Based on the changes in the signals returned by the superconducting quantum chip 130, the state of the qubits on the superconducting quantum chip 130 is obtained, that is, the quantum computing result is obtained.

[0081] It should be noted that the microwave manipulation pulse sequence may be input sequentially to the superconducting quantum chip 130, simultaneously to the superconducting quantum chip 130, or partially sequentially and partially simultaneously to the superconducting quantum chip 130. In contrast, the microwave measurement pulse signal is generally input simultaneously to the superconducting quantum chip 130.

[0082] Next, we will introduce the superconducting quantum chip 130.

[0083] See Figure 5 , Figure 5 This is a schematic diagram of the structure of a superconducting quantum chip 130 provided in an embodiment of this application. It includes a bit layer 131, a bit interaction layer 132, and a wiring transition layer 133, as well as multiple transmission lines 134 (not shown in the figure). The bit layer 131, bit interaction layer 132, and wiring transition layer 133 are stacked together. Wherein:

[0084] The bit layer 131 includes multiple qubits 1311 arranged in an alternating array and multiple couplers 1312. Each coupler 1312 can electromagnetically couple (e.g., capacitively or inductively) a pair of qubits 1311, and is used to adjust and control the coupling strength between the pair of qubits 1311, so that the pair of qubits 1311 can exchange energy or information under specific conditions, thereby realizing complex multi-qubit logic gate operations.

[0085] It should be noted that, Figure 5The multiple qubits 1311 and multiple couplers 1312 are arranged horizontally and vertically in a rectangular lattice array. In practice, the multiple qubits 1311 and multiple couplers 1312 can also be arranged in a triangular lattice array, a square lattice array, or a hexagonal lattice array. The embodiments of this application do not require a specific arrangement of the multiple qubits 1311 and multiple couplers 1312.

[0086] The bit interaction layer 132 includes multiple control lines 1321 arranged in an array, and multiple readout cavities 1322 arranged in an array. Each control line 1321 is electromagnetically coupled (e.g., capacitively coupled or inductively coupled) to a qubit 1311 for precise control of that qubit 1311. Furthermore, the control line 1321 can be an XY line or a Z line. The XY line is used to control the rotation of the qubit 1311 around the X-axis and / or Y-axis, i.e., to control the Pauli-X operation and / or Pauli-Y operation of the qubit 1311; the Z line is used to control the rotation of the qubit 1311 around the Z-axis, i.e., to control the Pauli-Z operation of the qubit 1311. Each readout cavity 1322 is also electromagnetically coupled (e.g., capacitively coupled or inductively coupled) to a qubit 1311 for reading the state of that qubit 1311.

[0087] It should be noted that there is a one-to-many relationship between qubit 1311 and control line 1321, while there is a one-to-one relationship between qubit 1311 and readout cavity 1322.

[0088] In practical applications, each control line 1321 connects to one or more transmission lines 134, and each readout cavity 1322 is electromagnetically coupled to one transmission line 134. The transmission line 134 connected to the control line 1321 can be called the input line 1341, and the transmission line 134 electromagnetically coupled to the readout cavity 1322 can be called the output line 1342. The input line 1341 is used to transmit a first microwave signal to the connected control line 1321. The output line 1342 is used to transmit a second microwave signal to the electromagnetically coupled readout cavity 1322 and output the state of the electromagnetically coupled qubit 1311 of this readout cavity 1322. The first microwave signal refers to the signal corresponding to the microwave control pulse sequence on an input line 1341, and the second microwave signal refers to the signal corresponding to the microwave measurement pulse signal on an output line 1342.

[0089] The following describes how a readout cavity 1322 reads the state of the corresponding qubit 1311.

[0090] Generally, the readout cavity 1322 reads the state of qubit 1311 in two ways: reflective readout and dangling readout.

[0091] See Figure 6a , Figure 6aThis is a schematic diagram of a reflective readout of the state of a quantum bit 1311 provided in an embodiment of this application. The output line 1342 transmits a second microwave signal to the readout cavity 1322. The readout cavity 1322 reads the state of the quantum bit 1311 based on the second microwave signal. Then, the read state is fed back to the output line 1342 in the form of a microwave signal. The fed-back microwave signal is transmitted in reverse in the output line 1342 and finally reaches the external signal receiver.

[0092] See Figure 6b , Figure 6b This is a schematic diagram of a suspended reading of the state of a quantum bit 1311 provided in an embodiment of this application. The output line 1342 transmits a second microwave signal to the readout cavity 1322. The readout cavity 1322 reads the state of the quantum bit 1311 based on the second microwave signal. Then, the read state is fed back to the output line 1342 in the form of a microwave signal. The fed-back microwave signal continues to be transmitted in the output line 1342 and finally reaches the external signal receiver.

[0093] In practical applications, both input line 1341 and output line 1342 are transmission lines 134 and need to be led outwards. When the number of qubits 1311 on the superconducting quantum chip 130 is lower than the set value, the number of transmission lines 134 required is also limited. The transmission lines 134 can be routed from the surface of the bit interaction layer 132 to the boundary and then led outwards (to the wiring transition layer 133).

[0094] The wiring transition layer 133 includes multiple solder points 1331 (formed using ball grid array packaging technology) and multiple connectors 1332 (not shown in the figure). The solder points 1331 may include a first solder point and a second solder point. The first solder point is used to connect multiple input lines 1341 extending from the boundary of the bit interaction layer 132. The second solder point is used to connect multiple output lines 1342 extending from the boundary of the bit interaction layer 132. The multiple connectors 1332 may include input connectors and output connectors. The input connector is connected to the first solder point for inputting a microwave control pulse sequence, and the output connector is connected to the second solder point for inputting a microwave measurement pulse signal.

[0095] See Figure 7 , Figure 7 This is a schematic diagram of the internal connections of a superconducting quantum chip 130 provided in an embodiment of this application. Figure 7Quantum bit 1311 is coupled to other qubits 1311 (not shown) via coupler 1312. This qubit 1311 corresponds to two control lines 1321, one being an XY line and the other a Z line. Each control line 1321 is connected to an input line 1341, the other end of which is connected to a first solder point. Additionally, this qubit 1311 corresponds to a readout cavity 1322, which electromagnetically couples an output line 1342, one end of which is connected to a second solder point. When the readout cavity 1322 reads the state of this qubit 1311 in a suspended manner, the other end of the output line 1342 is also connected to the second solder point (generally different from the second solder point connected to the other end); when the readout cavity 1322 reads the state of this qubit 1311 in a reflective manner, the other end of the output line 1342 is disconnected near the readout cavity 1322.

[0096] When the superconducting quantum chip 130 is required to perform quantum computing, the microwave control pulse sequence emitted by the microwave device first reaches the input terminal, and then reaches multiple input lines 1341 through the first solder point connected by the input terminal. These multiple input lines 1341 transmit the microwave control pulse sequence to the corresponding control line 1321 (the signal transmitted by each input line 1341 in this process is called the first microwave signal). Based on the microwave control pulse sequence, these control lines 1321 change the state of the corresponding qubit 1311, thereby realizing quantum computing.

[0097] After the quantum computation is completed, the microwave measurement pulse signal emitted by the microwave device first reaches the output terminal, then passes through the second solder joint connected to the input terminal, and finally reaches multiple output lines 1342. These multiple output lines 1342 transmit the microwave measurement pulse signal to the corresponding readout cavity 1322 (the signal transmitted by each output line 1342 in this process is called the second microwave signal). These readout cavities 1322 read the state of the corresponding qubit 1311 and feed back the read state as a microwave signal to these multiple output lines 1342. Then, the signal is output to the external signal receiving device through these multiple output lines 1342. Subsequently, the signal receiving device compares the received microwave signal with the microwave measurement pulse signal to obtain the quantum computation result.

[0098] It should be noted that, Figure 5 This description uses the separate bit layer 131 and bit interaction layer 132 as an example. In some embodiments, bit layer 131 and bit interaction layer 132 can also be combined into one layer (let's call it the computation layer). When combined into one layer, the control line 1321 and readout cavity 1322 corresponding to each quantum bit 1311 can be arranged around this quantum bit 1311. In this case, the transmission line 134 runs from the surface of the computation layer to the boundary and then extends outward.

[0099] However, as the number of qubits 1311 contained in the superconducting quantum chip 130 increases, the surface of the qubit interaction layer 132 or the computation layer is insufficient to accommodate transmission lines 134, leading to fan-out. To address this, a routing layer was proposed to solve the fan-out problem of the superconducting quantum chip 130. Specifically, vias are made at suitable locations for transmission lines 134 in the qubit interaction layer 132 or the computation layer. The transmission lines 134 are then routed through these vias to the routing layer, arranged within the routing layer, and then routed outwards. This eliminates the need to route the transmission lines 134 from the surface, optimizing the circuit layout and reducing crosstalk, thus effectively solving the fan-out problem.

[0100] See Figure 8 , Figure 8 This is a schematic diagram of another superconducting quantum chip 130 provided in an embodiment of this application. It includes a stacked bit layer 131, a bit interaction layer 132, a wiring layer 135, and a connection layer 133, as well as multiple transmission lines 134 (not shown). A silicon substrate (not shown) is located between the bit interaction layer 132 and the wiring layer 135, and the silicon substrate has vias (opened using through-silicon via technology). Each transmission line 134 is led out from the bit interaction layer 132, passes through the vias in the silicon substrate to reach the wiring layer 135, is arranged in the wiring layer 135, and then leads outwards.

[0101] Next, the structure of the wiring layer 135 will be introduced.

[0102] See Figure 9 , Figure 9 This is a schematic diagram of a trace layer 135 provided in an embodiment of this application. It includes multiple ground layers 1351, dielectrics 1352, multiple superconducting interconnect metals 1353, and multiple vias 1354. Each ground layer 1351 can be made of the same material as the transmission line 134, providing a unified reference potential such as signal ground, power ground, shielding ground, digital ground, analog ground, or local ground. The dielectrics 1352, such as silicon nitride or silicon oxide, fill the gaps to provide electrical isolation. Each superconducting interconnect metal 1353 can also be made of the same material as the transmission line 134, connecting two ground layers 1351. Each via 1354 is located where the routing of the transmission line 134 needs to be changed, allowing it to pass through the transmission line 134.

[0103] Figure 9 The transmission line 134 shown is a single transmission line that extends outwards after being arranged in three layers within dielectric 1352. Specifically, this transmission line 134 extends from a via on the silicon substrate to the ground layer 1351, which is closest to the silicon substrate. Figure 9The middle ground layer 1351 is the uppermost layer. The line enters the dielectric 1352 through the ground layer 1351. After being arranged in the Y direction in the dielectric 1352, it goes to the left through the ground layer 1351 directly below the transmission line 134. After being arranged in the opposite direction of the Y direction at the corresponding position on the left, it goes to the right through the ground layer 1351 directly below the transmission line 134. After being arranged in the Y direction at the corresponding position on the right, it is led out through a via 1354 (shown in the figure).

[0104] It should be noted that, Figure 9 For illustrative purposes only; in actual applications, a transmission line 134 may have fewer or more layers within the dielectric 1352. Generally, when the transmission line 134 is arranged in layers other than the last layer, there are grounding layers 1351 on both the top and bottom surfaces of the transmission line 134, and the space between the grounding layer 1351 and the transmission line 134 is filled with dielectric 1352, such as... Figure 10 As shown. Subsequently, the dielectric 1352 between adjacent ground layers 1351 will be referred to as the dielectric layer. Generally, the thicknesses of different dielectric layers can be the same or different.

[0105] The following is an introduction Figure 10 The impedance calculation method for transmission line 134 is shown.

[0106] See Figure 11 , Figure 11 This is a schematic diagram of the distribution of a transmission line 134 provided in an embodiment of this application. The transmission line 134 has a width of w, a thickness of t, a length of l in the dielectric layer, and a distance b (i.e., the thickness of the dielectric layer) between adjacent ground layers 1351. Therefore, the impedance Z of the transmission line 134 is:

[0107]

[0108] in,

[0109] L is the geometric inductance of transmission line 134, C is the capacitance of transmission line 134, V0 is the speed of light in vacuum, and ε r is the relative permittivity of the material used to prepare the dielectric layer.

[0110] It is evident that the geometric inductance L and capacitance C of transmission line 134 are closely related to the geometry of trace layer 135.

[0111] Because the dielectric materials commonly used in superconducting quantum chips 130 have high relative permittivity, it is difficult to reduce the capacitance C. Furthermore, the dynamic inductance of the material used to fabricate transmission lines 134 is very small, negligible compared to the geometric inductance. Therefore, related technologies aim to increase the impedance of transmission lines 134 by improving the geometric inductance. However, increasing the geometric inductance requires minimizing the size of transmission lines 134 and increasing the thickness of the dielectric layer. However, fabricating small-sized transmission lines 134 and thick, flat dielectric layers using micro / nano processes is challenging, making it difficult to increase the impedance of transmission lines 134 and achieve perfect impedance matching with microwave equipment.

[0112] Taking a microwave device with an impedance of 50Ω as an example. Assuming the dielectric layer is made of silicon nitride, with a relative permittivity of 9.2, and the transmission line 134 has a width of 2µm or 4µm (common values), a simulation is performed to demonstrate impedance matching achieved by increasing the geometric inductance. See [link to simulation]. Figure 12 , Figure 12 This is a simulation diagram illustrating the relationship between the impedance of transmission line 134 and the thickness of silicon nitride during impedance matching, provided for an embodiment of this application. The horizontal axis represents the thickness of the silicon nitride (i.e., the thickness of the dielectric layer), and the vertical axis represents the impedance of transmission line 134. It can be seen that to achieve impedance matching by increasing the geometric inductance, the thickness of the dielectric layer needs to be above 10 μm. This dimensional parameter is difficult to achieve in the fabrication of 130 micro-nano superconducting quantum chips, resulting in a relatively low yield.

[0113] Considering that some materials, such as titanium nitride, niobium nitride, aluminum nitride, tantalum nitride, niobium titanium nitrogen, granular aluminum, niobium silicon, and titanium aluminum nitrogen, are strong dynamic inductance materials (meaning that the dynamic inductance of the material is greater than a given value, such as 50 pH·nm / square), if these materials are used to prepare transmission line 134, transmission line 134 can have additional dynamic inductance. Dynamic inductance can increase the overall inductance of transmission line 134 on the basis of geometric inductance. Since the impedance of transmission line 134 is positively correlated with the overall inductance, the impedance of transmission line 134 can be increased.

[0114] when Figure 11 When the transmission line 134 shown is made of one or more of titanium nitride, niobium nitride, aluminum nitride, tantalum nitride, niobium titanium nitrogen, particulate aluminum, niobium silicon, and titanium aluminum nitrogen, the impedance Z of the transmission line 134 is:

[0115]

[0116] in, L is the geometric inductance of transmission line 134, and C is the capacitance of transmission line 134. ′denoted as α, where α is the dynamic inductance of transmission line 134, α is the dynamic inductance of the superconducting material used to fabricate transmission line 134, α is the length of transmission line 134, and β is the width of transmission line 134. Here, ρ is the reduced Planck constant, ρ is the resistivity of the superconducting material in its normal state, Δ(T) is the superconducting band gap of the superconducting material, and t is the thickness of the superconducting material, i.e., the thickness of transmission line 134. The formulas for calculating L and C are the same as those introduced earlier and will not be repeated here.

[0117] Thus, the impedance of transmission line 134 is determined by the dynamic inductance, geometric inductance, and capacitance of transmission line 134. The addition of dynamic inductance can increase the total inductance of transmission line 134, thereby increasing the impedance of transmission line 134. Therefore, the difference between the impedance of transmission line 134 and the impedance of microwave equipment can be further reduced, improving the impedance matching degree between transmission line 134 and microwave equipment.

[0118] In related technologies, increasing the geometric inductance to improve the impedance of transmission line 134 does not achieve an impedance of 30Ω. However, in this embodiment, by using a strong dynamic inductance material, the impedance of transmission line 134 can be increased to 30Ω or higher. Furthermore, simply replacing the material used to fabricate transmission line 134 with a strong dynamic inductance material is sufficient; there is no need to change the fabrication process of the superconducting quantum chip 130. Therefore, current micro-nano fabrication techniques can ensure a high yield rate.

[0119] Considering that the impedance of transmission line 134 is related not only to the type of material used in its fabrication, but also to the width, thickness, and dielectric layer thickness of transmission line 134, these parameters can be combined to improve the impedance of transmission line 134.

[0120] Assuming the width of transmission line 134 is between 2µm and 4µm, and the dielectric layer is made of silicon nitride, Figure 13 This diagram illustrates the relationship between the dynamic inductance of a transmission line and the thickness of silicon nitride, as provided in an embodiment of this application. It shows the dynamic inductance required for impedance matching for transmission lines 134 of different widths under different silicon nitride thicknesses. The horizontal axis represents the thickness of the silicon nitride layer, i.e., the thickness of the dielectric layer, and the vertical axis represents the dynamic inductance. It can be seen that the thinner the silicon nitride and the wider the transmission line 134, the greater the dynamic inductance required for impedance matching.

[0121] Based on a transmission line 134 width of 2µm and a silicon nitride thickness of 2µm, a comparison is made. Figure 12 and Figure 13 , Figure 12 In the absence of dynamic inductance, the impedance of transmission line 134 is approximately 22Ω. Figure 13In this configuration, when a dynamic inductance of 3.7 pH / square is introduced, transmission line 134 can achieve perfect impedance matching, meaning that the impedance of transmission line 134 can reach 50Ω.

[0122] In practical applications, even for the same type of high dynamic inductor material, the properties of different batches of this high dynamic inductor material, such as the sheet resistance ρ / t in the normal state and the superconducting transition temperature Δ(T), are different due to the influence of the preparation process and preparation conditions. These properties will affect the dynamic inductance of the high dynamic inductor material. Therefore, the dynamic inductance value of the high dynamic inductor material is not a fixed value, but will fluctuate within a certain range.

[0123] To facilitate the selection of a high dynamic inductance material for fabricating transmission line 134, a dynamic inductance range typically found in high dynamic inductance materials can be chosen, from 50 pH·nm / square to 3000 pH·nm / square. In other words, the cube dynamic inductance of the material used to fabricate transmission line 134 can be any value within the range of 50 pH·nm / square to 3000 pH·nm / square. Furthermore, to avoid increasing the fabrication difficulty of transmission line 134, its width can be any value between 2 μm and 4 μm.

[0124] The following section uses the example of a transmission line 134 with a strong dynamic inductance of 50 pH·nm / square to 3000 pH·nm / square and a width of 2µm to 4µm to illustrate the relationship between the thickness of the dielectric layer and the thickness of the transmission line 134 when the impedance of the transmission line 134 is perfectly matched with that of the microwave device.

[0125] Case 1: The dielectric layer is made of silicon nitride, and the transmission line 134 and the ground layer 1351 are both made of high dynamic inductance materials. Figures 14a to 14e This diagram illustrates the relationship between the thickness of the silicon nitride and the thickness of the transmission line 134 during impedance matching, as provided in an embodiment of this application. Wherein:

[0126] exist Figure 14aThe lower curve shows the variation of the thickness of transmission line 134 with the thickness of silicon nitride when the width of transmission line 134 is 2µm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 50 pH·nm / square, and the impedance of transmission line 134 is increased to 50Ω. Specifically, as the thickness of silicon nitride increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 1.47nm to 60.24nm. The upper curve shows the variation of the thickness of transmission line 134 with the thickness of silicon nitride when the width of transmission line 134 is 2µm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 3000 pH·nm / square, and the impedance of transmission line 134 is increased to 50Ω. Specifically, as the thickness of silicon nitride increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 88.47nm to 4000nm. Taking a silicon nitride thickness of 3000nm as an example, the straight line between the upper and lower curves represents the change in the thickness of the transmission line 134 with the block dynamic inductance of the transmission line 134 when the width of the transmission line 134 is 2um and the thickness of the silicon nitride is 3000nm, and the impedance of the transmission line 134 is increased to 50Ω.

[0127] exist Figure 14b The lower curve shows the variation of the thickness of transmission line 134 with the thickness of silicon nitride when the width of transmission line 134 is 2.5 μm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 50 pH·nm / square, and the impedance of transmission line 134 is increased to 50 Ω. Specifically, as the thickness of silicon nitride increases from 0 nm to 6000 nm, the thickness of transmission line 134 increases from 0.95 nm to 31.65 nm. The upper curve shows the variation of the thickness of transmission line 134 with the thickness of silicon nitride when the width of transmission line 134 is 2.5 μm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 3000 pH·nm / square, and the impedance of transmission line 134 is increased to 50 Ω. Specifically, as the thickness of silicon nitride increases from 0 nm to 6000 nm, the thickness of transmission line 134 increases from 56.95 nm to 1898.73 nm. Taking a silicon nitride thickness of 3000nm as an example, the straight line between the upper and lower curves represents the change in the thickness of the transmission line 134 with the block dynamic inductance of the transmission line 134 when the width of the transmission line 134 is 2.5um and the thickness of the silicon nitride is 3000nm, and the impedance of the transmission line 134 is increased to 50Ω.

[0128] exist Figure 14cThe lower curve represents the variation of the thickness of transmission line 134 with the thickness of silicon nitride when the width of transmission line 134 is 3µm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 50 pH·nm / square, and the impedance of transmission line 134 is increased to 50Ω. Specifically, as the thickness of silicon nitride increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 0.66nm to 20nm. The upper curve represents the variation of the thickness of transmission line 134 with the thickness of silicon nitride when the width of transmission line 134 is 3µm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 3000 pH·nm / square, and the impedance of transmission line 134 is increased to 50Ω. Specifically, as the thickness of silicon nitride increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 39.77nm to 1200nm. Taking a silicon nitride thickness of 3000nm as an example, the straight line between the upper and lower curves represents the change in the thickness of the transmission line 134 with the block dynamic inductance of the transmission line 134 when the width of the transmission line 134 is 3um and the thickness of the silicon nitride is 3000nm, and the impedance of the transmission line 134 is increased to 50Ω.

[0129] exist Figure 14d The lower curve represents the variation of the thickness of transmission line 134 with the thickness of silicon nitride when the width of transmission line 134 is 3.5 μm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 50 pH·nm / square, and the impedance of transmission line 134 is increased to 50 Ω. Specifically, as the thickness of silicon nitride increases from 0 nm to 6000 nm, the thickness of transmission line 134 increases from 0.49 nm to 14.01 nm. The upper curve represents the variation of the thickness of transmission line 134 with the thickness of silicon nitride when the width of transmission line 134 is 3.5 μm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 3000 pH·nm / square, and the impedance of transmission line 134 is increased to 50 Ω. Specifically, as the thickness of silicon nitride increases from 0 nm to 6000 nm, the thickness of transmission line 134 increases from 29.35 nm to 840.34 nm. Taking a silicon nitride thickness of 3000nm as an example, the straight line between the upper and lower curves represents the change in the thickness of the transmission line 134 with the block dynamic inductance of the transmission line 134 when the width of the transmission line 134 is 3.5um and the thickness of the silicon nitride is 3000nm, and the impedance of the transmission line 134 is increased to 50Ω.

[0130] exist Figure 14eThe lower curve shows the variation of the thickness of transmission line 134 with the thickness of silicon nitride when the width of transmission line 134 is 4µm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 50 pH·nm / square, and the impedance of transmission line 134 is increased to 50Ω. Specifically, as the thickness of silicon nitride increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 0.3nm to 10.37nm. The upper curve shows the variation of the thickness of transmission line 134 with the thickness of silicon nitride when the width of transmission line 134 is 4µm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 3000 pH·nm / square, and the impedance of transmission line 134 is increased to 50Ω. Specifically, as the thickness of silicon nitride increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 22.53nm to 622.41nm. Taking a silicon nitride thickness of 3000nm as an example, the straight line between the upper and lower curves represents the change in the thickness of the transmission line 134 with the block dynamic inductance of the transmission line 134 when the width of the transmission line 134 is 4um and the thickness of the silicon nitride is 3000nm, and the impedance of the transmission line 134 is increased to 50Ω.

[0131] from Figures 14a to 14e It can be seen that the thickness of the transmission line 134 that achieves complete impedance matching ranges from 0.3 nm to 4000 nm, and the thickness range of the transmission line 134 also narrows as the width of the transmission line 134 decreases.

[0132] Case 2: The dielectric layer is made of silicon oxide, and the transmission line 134 and the ground layer 1351 are both made of high dynamic inductance materials.

[0133] See Figure 15 , Figure 15 This diagram illustrates the relationship between the dynamic inductance of a transmission line 134 and the thickness of silicon oxide, as provided in an embodiment of this application. It shows the dynamic inductance required to achieve impedance matching for transmission lines 134 of different widths and under different silicon oxide thicknesses. The horizontal axis represents the thickness of the silicon oxide, and the vertical axis represents the dynamic inductance of the transmission line 134. It can be seen that the smaller the silicon oxide thickness and the wider the transmission line 134, the greater the dynamic inductance required to achieve complete impedance matching.

[0134] See Figures 16a to 16e , Figures 16a to 16e This diagram illustrates the relationship between the thickness of silicon oxide and the thickness of the transmission line during impedance matching, as provided in an embodiment of this application. Wherein:

[0135] exist Figure 16aThe lower curve represents the variation of the thickness of transmission line 134 with the thickness of silicon oxide when the width of transmission line 134 is 2µm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 50 pH·nm / square, and the impedance of transmission line 134 is increased to 50Ω. Specifically, as the thickness of silicon oxide increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 3.41nm to 5000nm. The upper curve represents the variation of the thickness of transmission line 134 with the thickness of silicon oxide when the width of transmission line 134 is 2µm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 3000 pH·nm / square, and the impedance of transmission line 134 is increased to 50Ω. Specifically, as the thickness of silicon oxide increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 200nm to 6000nm. Taking a silicon oxide thickness of 3000nm as an example, the straight line between the upper and lower curves represents the change in the thickness of the transmission line 134 with the block dynamic inductance of the transmission line 134 when the width of the transmission line 134 is 2um and the thickness of the silicon oxide is 3000nm, and the impedance of the transmission line 134 is increased to 50Ω.

[0136] exist Figure 16b The lower curve represents the variation of the thickness of transmission line 134 with the thickness of silicon oxide when the width of transmission line 134 is 2.5 μm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 50 pH·nm / square, and the impedance of transmission line 134 is increased to 50 Ω. Specifically, as the thickness of silicon oxide increases from 0 nm to 6000 nm, the thickness of transmission line 134 increases from 2.19 nm to 1800 nm. The upper curve represents the variation of the thickness of transmission line 134 with the thickness of silicon oxide when the width of transmission line 134 is 2.5 μm, the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 3000 pH·nm / square, and the impedance of transmission line 134 is increased to 50 Ω. Specifically, as the thickness of silicon oxide increases from 0 nm to 6000 nm, the thickness of transmission line 134 increases from 131.58 nm to 6000 nm. Taking a silicon oxide thickness of 3000nm as an example, the straight line between the upper and lower curves represents the change in the thickness of the transmission line 134 with the block dynamic inductance of the transmission line 134 when the width of the transmission line 134 is 2.5um and the thickness of the silicon oxide is 3000nm, and the impedance of the transmission line 134 is increased to 50Ω.

[0137] exist Figure 16cThe curve below shows the variation of the thickness of transmission line 134 with the thickness of silicon oxide when the width of transmission line 134 is 3µm and the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 50 pH·nm / square, in order to increase the impedance of transmission line 134 to 50Ω. Specifically, as the thickness of silicon oxide increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 1.53nm to 440nm. The curve above shows the variation of the thickness of transmission line 134 with the thickness of silicon oxide when the width of transmission line 134 is 3µm and the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 3000 pH·nm / square, in order to increase the impedance of transmission line 134 to 50Ω. Specifically, as the thickness of silicon oxide increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 91.74nm to 6000nm. Taking a silicon oxide thickness of 3000nm as an example, the straight line between the upper and lower curves represents the change in the thickness of the transmission line 134 with the block dynamic inductance of the transmission line 134 when the width of the transmission line 134 is 3um and the thickness of the silicon oxide is 3000nm, in order to increase the impedance of the transmission line 134 to 50Ω.

[0138] exist Figure 16d The curve below shows the variation of the thickness of transmission line 134 with the thickness of silicon oxide when the width of transmission line 134 is 3.5 μm and the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 50 pH·nm / square, in order to increase the impedance of transmission line 134 to 50 Ω. Specifically, as the thickness of silicon oxide increases from 0 nm to 6000 nm, the thickness of transmission line 134 increases from 1.13 nm to 156.25 nm. The curve above shows the variation of the thickness of transmission line 134 with the thickness of silicon oxide when the width of transmission line 134 is 3.5 μm and the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 3000 pH·nm / square, in order to increase the impedance of transmission line 134 to 50 Ω. Specifically, as the thickness of silicon oxide increases from 0 nm to 6000 nm, the thickness of transmission line 134 increases from 67.64 nm to 6000 nm. Taking a silicon oxide thickness of 3000nm as an example, the straight line between the upper and lower curves represents the change in the thickness of the transmission line 134 with the block dynamic inductance of the transmission line 134 when the width of the transmission line 134 is 3.5um and the thickness of the silicon oxide is 3000nm, in order to increase the impedance of the transmission line 134 to 50Ω.

[0139] exist Figure 16eThe lower curve shows the variation of the thickness of transmission line 134 with the thickness of silicon oxide when the width of transmission line 134 is 4µm and the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 50 pH·nm / square, in order to increase the impedance of transmission line 134 to 50Ω. Specifically, as the thickness of silicon oxide increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 0.8nm to 64.94nm. The upper curve shows the variation of the thickness of transmission line 134 with the thickness of silicon oxide when the width of transmission line 134 is 4µm and the sheet dynamic inductance of the high dynamic inductance material used to fabricate transmission line 134 is 3000 pH·nm / square, in order to increase the impedance of transmission line 134 to 50Ω. Specifically, as the thickness of silicon oxide increases from 0nm to 6000nm, the thickness of transmission line 134 increases from 51.84nm to 3896.10nm. Taking a silicon oxide thickness of 3000nm as an example, the straight line between the upper and lower curves represents the change in the thickness of the transmission line 134 with the block dynamic inductance of the transmission line 134 when the width of the transmission line 134 is 4um and the thickness of the silicon oxide is 3000nm, in order to increase the impedance of the transmission line 134 to 50Ω.

[0140] From the comparison Figures 16a to 16e It can be seen that the thickness range of the impedance matching transmission line 134 is from 0.8 nm to 6000 nm (reaching the maximum thickness of the dielectric layer), and as the width of the transmission line 134 decreases, the thickness range of the transmission line 134 also narrows.

[0141] It should be noted that, Figures 16a to 16c In the simulation, the thickness range of transmission line 134 narrows as the silicon oxide thickness increases. This is because the thickness of transmission line 134 required to achieve complete impedance matching exceeds the thickness of the dielectric layer during simulation. In reality, the maximum thickness of transmission line 134 can only reach the thickness of the dielectric layer. Therefore, the thickness of the dielectric layer is taken as the thickness of transmission line 134.

[0142] In this embodiment, the transmission line 134 is fabricated using a highly dynamic inductor material, giving it dynamic inductance. This dynamic inductance enhances the impedance of the transmission line 134. The thickness range of the dielectric layer and the size range of the transmission line 134 are also provided for achieving complete impedance matching between the transmission line 134 and the microwave device. Since the thickness and size ranges have relatively low requirements for the fabrication process, the yield and fabrication efficiency of the superconducting quantum chip 130 can be improved.

[0143] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope and intent of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and variations.

Claims

1. A superconducting quantum chip, characterized in that, The superconducting quantum chip includes a transmission line, a control line, and a quantum bit. The transmission line includes an input line, which is connected to the control line. The control line is electromagnetically coupled to the quantum bit. The input line is used to transmit the first microwave signal from the microwave device to the control line; The control line is used to change the state of the qubit based on the first microwave signal in order to realize quantum computing; The difference between the impedance of the transmission line and the impedance of the microwave device is less than a preset value, and the impedance of the transmission line is determined based on the dynamic inductance, geometric inductance, and capacitance of the transmission line.

2. The superconducting quantum chip as described in claim 1, characterized in that, The superconducting quantum chip further includes a readout cavity, the transmission line further includes an output line, the quantum bit is electromagnetically coupled to the readout cavity, and the readout cavity is electromagnetically coupled to the output line; The output line is used to transmit the second microwave signal of the microwave device to the readout cavity; It is also used to output the state of the qubit after quantum computing; The readout cavity is used to read the state of the qubit after quantum computing based on the second microwave signal, and to feed back the read state to the output line.

3. The superconducting quantum chip as described in claim 1 or 2, characterized in that, The cube dynamic inductance of the material used to fabricate the transmission line is greater than or equal to 50 picohens and less than or equal to 3000 picohens. The cube dynamic inductance refers to the dynamic inductance of a cuboid made of the material along its length. The thickness of the cuboid is 1 nanometer, and the length and width of the cuboid are equal.

4. The superconducting quantum chip as described in claim 3, characterized in that, The width of the transmission line is greater than or equal to 2 micrometers and less than or equal to 4 micrometers.

5. The superconducting quantum chip as described in claim 4, characterized in that, The superconducting quantum chip also includes a wiring layer for arranging the transmission lines. When the dielectric material in the wiring layer is silicon nitride, the thickness of the transmission lines is greater than or equal to 0.3 nanometers and less than or equal to 4000 nanometers.

6. The superconducting quantum chip as described in claim 4, characterized in that, The superconducting quantum chip also includes a wiring layer for arranging the transmission lines. When the dielectric material in the wiring layer is silicon oxide, the thickness of the transmission lines is greater than or equal to 0.8 nanometers and less than or equal to 6000 nanometers.

7. The superconducting quantum chip as described in claim 1 or 2, characterized in that, The transmission line is made of one or more of the following materials: Titanium nitride, niobium nitride, aluminum nitride, tantalum nitride, niobium titanium nitrogen, particulate aluminum, niobium silicon, titanium aluminum nitrogen.

8. The superconducting quantum chip as described in claim 1 or 2, characterized in that, The impedance of the microwave device is 50 ohms.

9. The superconducting quantum chip as described in claim 8, characterized in that, The impedance of the transmission line is greater than or equal to 30 ohms.

10. A superconducting quantum computer, characterized in that, Includes measurement and control equipment, a superconducting quantum chip as described in any one of claims 1 to 9, and a dilution refrigerator, wherein: The measurement and control equipment is used to control the microwave equipment to send microwave signals to the superconducting quantum chip; The superconducting quantum chip is used for quantum computing based on the microwave signal; The dilution refrigerator is used to provide the ambient temperature required for quantum computing for the superconducting quantum chip.

Images