Superconducting Quantum Bit Coupling Method and Device, Electronic Device, Computer Medium

Abstract

The present disclosure provides a superconducting qubit coupling method and apparatus, relating to the technical field of superconducting quantum chips. The specific implementation scheme is as follows: determining a target coupling strength between a target readout cavity and a qubit, a first target frequency of the qubit, and a second target frequency of the target readout cavity; initializing a layout of a readout coupling port configuration based on the configuration of the qubit and the relative position between the qubit and the target readout cavity; calculating a to-be-detected coupling strength between the qubit and the readout coupling port based on the layout of the readout coupling port configuration, the first target frequency, and the second target frequency; and generating a complete layout including the qubit and the target readout cavity based on the second target frequency and the layout of the readout coupling port configuration in response to detecting that the to-be-detected coupling strength meets a preset condition. This implementation mode improves the design efficiency of the readout cavity.

Description

Technical Field

[0001] The present disclosure relates to the field of quantum computing technology, specifically to the field of superconducting quantum chip technology, and particularly to a superconducting qubit coupling method and apparatus, an electronic device, a computer-readable medium, and a computer program product. Background Art

[0002] As the heart of quantum computing, the quantum chip occupies a very important position. The core part of the superconducting quantum chip design includes the design of qubits and readout cavities. Among them, the qubit is a unit of quantum computing, and the readout cavity is another important unit used to indirectly read the state of the qubit. The main design indicators of the readout cavity include the frequency of the readout cavity itself, the quality factor of the readout cavity, and the coupling strength between the readout cavity and the qubit. For the coupling between the readout cavity and the qubit, too weak coupling affects the readout efficiency of the qubit, and too strong coupling brings more noise to the qubit.

[0003] Currently, the design of the read coupling port in the industry is usually regarded as a black box. It is necessary to first design a preliminary complete layout of the qubit and the readout cavity, then calculate the coupling strength between the qubit and the readout cavity through electromagnetic simulation methods, and perform iterative design of the read coupling port according to the difference from the target coupling strength. This method is actually very inefficient in the quantum chip design stage. Summary of the Invention

[0004] A superconducting qubit coupling method and apparatus, an electronic device, a computer-readable medium, and a computer program product are provided.

[0005] According to a first aspect, a superconducting qubit coupling method is provided. The method includes: determining a target coupling strength between a target readout cavity and a qubit, a first target frequency of the qubit, and a second target frequency of the target readout cavity; initializing a read coupling port configuration layout based on the configuration of the qubit and the relative position between the qubit and the target readout cavity, where the read coupling port configuration layout is a layout for characterizing the positional relationship between the qubit and the read coupling port of the target readout cavity; calculating a to-be-detected coupling strength between the qubit and the read coupling port based on the read coupling port configuration layout, the first target frequency, and the second target frequency; and generating a complete layout including the qubit and the target readout cavity based on the second target frequency and the read coupling port configuration layout in response to detecting that the to-be-detected coupling strength and the target coupling strength meet a preset condition.

[0006] According to a second aspect, a superconducting qubit coupling device is provided, the device comprising: a determination unit configured to determine a target coupling strength between a target readout cavity and a qubit, a first target frequency of the qubit, and a second target frequency of the target readout cavity; an initialization unit configured to initialize a read coupling port configuration layout based on the configuration of the qubit and the relative position between the qubit and the target readout cavity, the read coupling port configuration layout being a layout for characterizing the positional relationship between the qubit and the read coupling port of the target readout cavity; a calculation unit configured to calculate a coupling strength to be measured between the qubit and the read coupling port based on the read coupling port configuration layout, the first target frequency, and the second target frequency; and a generation unit configured to generate a complete layout including the qubit and the target readout cavity based on the second target frequency and the read coupling port configuration layout in response to detecting that the coupling strength to be measured and the target coupling strength meet a preset condition.

[0007] According to a third aspect, an electronic device is provided, the electronic device comprising: at least one processor; and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method described in any implementation manner of the first aspect.

[0008] According to a fourth aspect, a non-transitory computer-readable storage medium storing computer instructions is provided, the computer instructions being used to cause a computer to execute the method described in any implementation manner of the first aspect.

[0009] According to a fifth aspect, a computer program product is provided, including a computer program which, when executed by a processor, implements the method described in any implementation manner of the first aspect.

[0010] The superconducting qubit coupling method and device provided by the embodiments of the present disclosure first determine the target coupling strength between the target read cavity and the qubit, the first target frequency of the qubit, and the second target frequency of the target read cavity; secondly, based on the configuration of the qubit and the relative position between the qubit and the target read cavity, initialize the layout of the read coupling port configuration, which is used to represent the layout of the positional relationship between the qubit and the read coupling port of the target read cavity; thirdly, calculate the coupling strength to be measured between the qubit and the read coupling port based on the layout of the read coupling port configuration, the first target frequency, and the second target frequency; finally, in response to detecting that the coupling strength to be measured satisfies a preset condition with the target coupling strength, generate a complete layout including the qubit and the target read cavity based on the second target frequency and the layout of the read coupling port configuration. The present disclosure only needs to focus on the layout of the read coupling port configuration reflecting the positional relationship between the qubit and the read coupling port, and can calculate the coupling strength to be measured without completely designing the layout of the entire read cavity, which greatly improves the design efficiency of the read cavity.

[0011] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings are used to better understand the solution and do not constitute a limitation to the present disclosure. Among them:

[0013] Figure 1 is a flowchart of an embodiment of the superconducting qubit coupling method according to the present disclosure;

[0014] Figure 2 is a schematic structural diagram of a layout of a read coupling port configuration in an embodiment of the present disclosure;

[0015] Figure 3 is a schematic structural diagram of a complete layout in an embodiment of the present disclosure;

[0016] Figure 4 is a flowchart of another embodiment of the superconducting qubit coupling method according to the present disclosure;

[0017] Figure 5 is a schematic structural diagram of an embodiment of the superconducting qubit coupling device according to the present disclosure;

[0018] Figure 6 is a block diagram of an electronic device for implementing the superconducting qubit coupling method of the embodiments of the present disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following describes exemplary embodiments of the present disclosure with reference to the accompanying drawings. Various details of the embodiments of the present disclosure are included to facilitate understanding, and they should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, descriptions of well-known functions and structures are omitted below for clarity and conciseness.

[0020] To better understand the method provided by the embodiments of the present disclosure, the following explains related concepts involved in the embodiments of the present disclosure.

[0021] A quantum chip integrates quantum circuits on a substrate and thus bears the function of quantum information processing.

[0022] As the limit of classical Moore's law is gradually approaching, quantum computing is considered the next-generation new computing mode, and is expected to demonstrate stronger computing power than classical computing in many complex problems, providing a solution efficiency improvement with at most exponential acceleration. It is particularly noteworthy that the realization of quantum applications highly depends on the development of quantum hardware. In the technical implementation of quantum hardware, there are several different technical solutions in the industry, such as superconducting circuits, ion traps, semiconductors, optical quantum systems, etc. Benefiting from good scalability and mature semiconductor processes, the design, research, and manufacturing of superconducting quantum chips integrating multiple superconducting qubits are of great significance. Many innovative companies or research institutions in the field of quantum computing have successively launched their own superconducting quantum chips.

[0023] Recently, the number of qubits integrated on superconducting quantum chips has been increasing, from several to dozens, and then to hundreds and thousands. The subsequent goal is to integrate millions of qubits.

[0024] The core part of the design of a superconducting quantum chip includes the design of qubits and readout cavities. Among them, qubits serve as quantum computing units, while readout cavities are another important unit used to indirectly read the states of qubits. The main design indicators of readout cavities include the frequency of the readout cavity itself, the quality factor of the readout cavity, and the coupling strength between the readout cavity and qubits. The frequency and quality factor of the readout cavity itself can be adjusted by adjusting its own length and coupling with the outside world. For the coupling between the readout cavity and qubits, too weak coupling affects the readout efficiency of qubits, while too strong coupling brings more noise to qubits and thus affects the coherence time of qubits. Therefore, precise design of the coupling ports between the readout cavity and qubits is required to achieve a specific target readout coupling strength.

[0025] Figure 1 FIG. 100 shows a flow of an embodiment according to the superconducting qubit coupling method of the present disclosure. The superconducting qubit coupling method includes the following steps:

[0026] Step 101: Determine the target coupling strength between the target readout cavity and the qubit, the first target frequency of the qubit, and the second target frequency of the target readout cavity.

[0027] In this embodiment, the core part of the superconducting quantum chip design includes the design of the qubit and the readout cavity. Among them, the two-level structure of the qubit is precisely designed as the quantum computing unit, and the readout cavity is another important component used to indirectly read the state of the qubit. The readout cavity is directly coupled to the superconducting qubit, forming a dispersive coupling relationship, that is, the frequency difference between the qubit and the readout cavity is much larger than the coupling strength between the two. Dispersive coupling requires the frequency difference between the qubit and the readout cavity to be greater than 1 GHz, and the target coupling strength is usually between 30 - 60 MHz.

[0028] Dispersive coupling will cause a dispersive shift between the qubit and the readout cavity, and the shift relationship is shown in Equation (1).

[0029]

[0030] Among them, in Equation (1), Δ is the frequency detuning amount between the qubit and the readout cavity, g is the coupling strength between the qubit and the readout cavity, and χ is the dispersive shift amount. As can be seen from Equation (1), the relevant information of the qubit is indirectly obtained by the state change of the readout cavity, that is, its dispersive shift amount, so as to realize the state reading of the qubit.

[0031] In this embodiment, in the superconducting quantum chip design scheme, there is the first target frequency of the qubit and the target coupling strength between the qubit and the target readout cavity. The second target frequency can be directly read from the superconducting quantum chip design scheme. Optionally, based on the dispersive coupling relationship between the qubit and the target readout cavity, the second target frequency can also be directly calculated from the first target frequency.

[0032] Step 102: Initialize the layout of the readout coupling port configuration based on the configuration of the qubit and the relative position between the qubit and the target readout cavity.

[0033] In this embodiment, the layout of the readout coupling port configuration is a layout used to characterize the positional relationship between the readout coupling ports of the qubit and the target readout cavity.

[0034] When designing the target reading cavity, the target reading cavity is generally implemented by a coplanar waveguide of standard impedance, wherein, in the target reading cavity layout, by reasonably designing the ratio of the center conductor width of the coplanar waveguide to the metal ground width on both sides of the center conductor width, the impedance of the target reading cavity can be kept at the standard impedance. In addition, for the reading cavity of standard impedance, the coupling mutual capacitance between the reading cavity and the quantum bit is only related to the configuration of the adjacent coupling port. For this reason, the coupling strength between the quantum bit and the target reading cavity can be calculated without requiring a complete reading cavity layout, and only the reading coupling port configuration layout of the reading cavity and the quantum bit is required. The coupling strength is the unverified coupling strength and is the coupling strength to be measured.

[0035] There are many configurations of quantum bits in superconducting quantum chips, including: cross configuration, symmetrical micon configuration, quasi-cross configuration, coplanar parallel plate configuration, etc. Among them, the cross configuration is obtained by connecting a cross-shaped capacitor with a superconducting Josephson junction, such as Figure 2 As shown, the cross-shaped structure is a cross-configuration quantum bit, the upper end of the quantum bit is coupled with a control line (used to manipulate the quantum bit), the left end of the quantum bit is used to set a superconducting Josephson junction, the right end of the quantum bit is coupled with a reading cavity (also known as a reading resonant cavity, used to read the information of the quantum bit), and the lower end of the quantum bit can be coupled with a bus (used to achieve interaction between different quantum bits). The symmetric rice configuration is a quantum bit formed by a symmetric rice capacitor, which is similar to the Chinese character "米". The right cross and the oblique cross in the "米" character each have equal side lengths, so the whole is symmetrical. The cross-like configuration is based on the cross-shaped quantum bit, and some structures are added. The cross-like quantum bit is to apply the chip structure in which superconducting quantum bits and chip lines are distributed in different layers. The capacitor of the coplanar parallel plate configuration is composed of two coplanar parallel plates, and the middle of the two plates is connected using a superconducting Josephson junction to form a quantum bit.

[0036] In this embodiment, in the design scheme of the superconducting quantum chip, the configuration requirements of the quantum bit and the positional relationship between the quantum bit and the target reading cavity are provided, and the configuration of the quantum bit and the positional relationship between the quantum bit and the target reading cavity can be directly read from the superconducting quantum chip, and the specific shape of the quantum bit is determined based on the configuration of the quantum bit; based on the positional relationship between the quantum bit and the target reading cavity, the first positional relationship between the reading coupling port between the quantum bit and the target reading cavity is determined, and based on the shape of the quantum bit and the first positional relationship, the configuration layout of the reading coupling port is designed. For example, Figure 1 As shown, the initialized read coupling port configuration layout is a layout that uses a cross-finger coupling configuration to improve the coupling strength.

[0037] In this embodiment, based on the configuration of qubits and the positional relationship between qubits and the target readout cavity in the superconducting quantum chip design, other configuration methods (such as the plug-in coupling configuration) can be used to obtain the layout of the readout coupling port configuration.

[0038] Step 103: Calculate the coupling strength to be measured between the qubit and the readout coupling port based on the layout of the readout coupling port configuration, the first target frequency, and the second target frequency.

[0039] In this embodiment, step 103 includes: performing electromagnetic simulation on the layout of the readout coupling port configuration, and the self-capacitance of the qubit, the coupling mutual capacitance between the qubit and the readout coupling end, and the port self-capacitance of the readout coupling end can be obtained. Substituting the self-capacitance of each qubit, the coupling mutual capacitance, the port self-capacitance, the first target frequency, and the second target frequency into the formula for the strength to be measured, the coupling strength to be measured can be obtained. Among them, the formula for the strength to be measured is used to represent the corresponding relationship among the self-capacitance of each qubit, the coupling mutual capacitance, the port self-capacitance, the first target frequency, the second target frequency, and the coupling strength to be measured. In this embodiment, the formula for the strength to be measured is a conventional formula for calculating the coupling strength through self-capacitance, coupling mutual capacitance, and frequency, as shown in Equation (2), and will not be elaborated here.

[0040] Step 104: In response to detecting that the coupling strength to be measured satisfies the preset condition with the target coupling strength, generate a complete layout including the qubit and the target readout cavity based on the second target frequency and the layout of the readout coupling port configuration.

[0041] In this embodiment, since the target coupling strength can be a preset value, the preset condition is set for the coupling strength to be measured and is related to the target coupling strength. The preset condition is used to determine whether the coupling strength to be measured satisfies the preset relational expression. There is a position for the target coupling strength in the preset relational expression. After obtaining the target coupling strength, first input the target coupling strength into the preset relational expression to generate a target relational expression. For example, the target relational expression is that the difference between the coupling strength to be measured and the target coupling strength is less than or equal to the preset target value (the preset target value can be adjusted according to requirements. For example, the preset target value is 0.1).

[0042] In this embodiment, the coupling strength to be measured can be the coupling strength calculated by iteratively adjusting the layout of the readout coupling port each time. For the coupling strength to be measured calculated by adjusting the layout of the readout coupling port each time, input the coupling strength to be measured this time into the target relational expression, and determine whether the target relational expression holds. If the target relational expression holds, it is determined that the coupling strength to be measured obtained this time satisfies the preset condition with the target coupling strength.

[0043] In this embodiment, the generation of the complete layout including the qubit and the target readout cavity based on the second target frequency and the layout of the readout coupling port configuration includes: based on the second target frequency, completing the readout coupling port, and a complete layout including the qubit and the target readout cavity can be generated.

[0044] As Figure 3 shown is a complete layout including the qubit feature and the target readout cavity Q after completing the readout coupling port. In Figure 3 it, the gray shaded part represents the superconducting metal layer, and the white part represents the etched part of the metal layer. The left cross metal layer structure is the cross configuration of the qubit L, and the right curved serpentine structure is the configuration of the target readout cavity Q. The interdigital part where the qubit and the target readout cavity are adjacent is the readout coupling port D, and the large shaded part on the outside of the rest is the ground metal layer. There is an etched part between the device and the ground metal layer to form the self-capacitance of the device, and the coupling mutual capacitance is formed between the devices.

[0045] The superconducting qubit coupling method provided by the embodiment of the present disclosure, when designing the readout cavity, only focuses on the layout of the readout coupling port configuration between the readout cavity and the qubit, which greatly simplifies the layout design, simulation and iteration, accelerates the design and simulation process of the entire readout coupling port, significantly reduces the number of iterations, efficiently realizes the target coupling strength between the qubit and the readout cavity, and greatly improves the design efficiency of the readout cavity.

[0046] The superconducting qubit coupling method provided by the embodiment of the present disclosure, first, determines the target coupling strength between the target readout cavity and the qubit, the first target frequency of the qubit, and the second target frequency of the target readout cavity; second, initializes the layout of the readout coupling port configuration based on the configuration of the qubit and the relative position between the qubit and the target readout cavity, and the layout of the readout coupling port configuration is used to characterize the layout of the positional relationship between the readout coupling ports of the qubit and the target readout cavity; third, calculates the to-be-detected coupling strength between the qubit and the readout coupling port based on the layout of the readout coupling port configuration, the first target frequency, and the second target frequency; finally, in response to detecting that the to-be-detected coupling strength and the target coupling strength meet the preset conditions, generates a complete layout including the qubit and the target readout cavity based on the second target frequency and the layout of the readout coupling port configuration. The present disclosure only needs to focus on the layout of the readout coupling port configuration reflecting the positional relationship between the qubit and the readout coupling port to calculate the to-be-detected coupling strength, without completely designing the layout of the entire readout cavity, which greatly improves the design efficiency of the readout cavity.

[0047] In one embodiment of the present disclosure, the above superconducting qubit coupling method may further include: in response to detecting that the measured coupling strength does not meet the preset condition with the target coupling strength, adjusting the spacing between the readout coupling port and the qubit in the readout coupling port configuration layout to obtain a new readout coupling port configuration layout; replacing the readout coupling port configuration layout with the new readout coupling port configuration layout; and continuing to calculate the measured coupling strength between the qubit and the readout coupling port based on the readout coupling port configuration layout, the first target frequency, and the second target frequency until it is detected that the measured coupling strength meets the preset condition with the target coupling strength.

[0048] In this embodiment, the spacing between the readout coupling port and the qubit refers to the actual distance between the qubit feature and the coupling port. When the actual distance between the readout coupling port and the qubit is large, the coupling strength between the two is small; when the actual distance between the readout coupling port and the qubit is small, the coupling strength between the two is large.

[0049] In this embodiment, after detecting that the measured coupling strength meets the preset condition with the target coupling strength, a complete layout including the qubit and the target readout cavity is generated based on the second target frequency and the readout coupling port configuration layout.

[0050] In this embodiment, the readout coupling port configuration layout can be obtained after adjusting the specifications of the readout coupling port in the layout or the spacing between the qubit and the readout coupling port multiple times.

[0051] The superconducting qubit coupling method provided in this embodiment, when detecting that the measured coupling strength does not meet the preset condition with the target coupling strength, adjusts the spacing between the readout coupling port and the qubit in the readout coupling port configuration layout, so that the spacing between the readout coupling port and the qubit changes until a target readout cavity that meets the second target frequency and the target coupling strength is achieved, simplifies the layout design and simulation, accelerates the design efficiency of the target readout cavity, and provides another reliable implementation method for the measured coupling strength to meet the preset condition with the target coupling strength.

[0052] Figure 4 Flow 400 shows another embodiment of the superconducting qubit coupling method according to the present disclosure. The above superconducting qubit coupling method includes the following steps:

[0053] Step 401, determining the target coupling strength between the target readout cavity and the qubit, the first target frequency of the qubit, and the second target frequency of the target readout cavity, and then performing step 402.

[0054] Step 402: Initialize the layout of the read coupling port based on the configuration of the qubits and the relative positions of the qubits and the target read cavity. Then, execute Step 403.

[0055] Step 403: Calculate the coupling strength to be measured between the qubits and the read coupling port based on the layout of the read coupling port, the first target frequency, and the second target frequency. Then, execute Step 404.

[0056] Step 404: Detect whether the coupling strength to be measured meets the preset conditions; if it is detected that the preset conditions are met, execute Step 405; if it is detected that the preset conditions are not met, execute Step 407.

[0057] Step 405: Generate a complete layout including the qubits and the target read cavity based on the second target frequency and the layout of the read coupling port. Then, execute Step 406.

[0058] It should be understood that the operations and features in the above Steps 401 - 405 respectively correspond to the operations and features in Steps 101 - 104. Therefore, the descriptions of the operations and features in Steps 101 - 104 above also apply to Steps 401 - 405 and will not be repeated here.

[0059] Optionally, for Figure 4 the embodiment shown, the superconducting qubit coupling method provided by the present disclosure may further include: performing electromagnetic simulation on the complete layout to obtain the self - capacitance of the qubits and the mutual capacitance of the coupling between the qubits and the target read cavity; calculating the calculated coupling strength based on the self - capacitance of the qubits, the mutual capacitance of the coupling, the first target frequency, and the second target frequency; and determining that the complete layout is correct in response to detecting that the calculated coupling strength meets the preset conditions.

[0060] Step 406: Exit.

[0061] Step 407: Adjust the specifications of the read coupling ports in the layout of the read coupling port to obtain a new layout of the read coupling port. Then, execute Step 408.

[0062] In this embodiment, the adjustment of the specifications of the read coupling ports can be adaptively adjusted based on the shape of the read coupling ports. As Figure 2 shown, the shape of the read coupling ports is finger - like, and a new layout of the read coupling port can be obtained by adjusting the length a of the first finger part of the read coupling port.

[0063] Step 408: Replace the layout of the read coupling port with the new layout of the read coupling port and execute Step 403.

[0064] The superconducting qubit coupling method provided in this embodiment adjusts the specifications of the readout coupling ports in the readout coupling port configuration layout when it is detected that the coupling strength to be measured does not meet the preset conditions, so that the shape of the readout coupling ports changes until a target readout cavity that meets the second target frequency and the target coupling strength is achieved, simplifies the layout design and simulation, accelerates the design efficiency of the target readout cavity, and provides a reliable implementation method for the coupling strength to be measured to meet the preset conditions.

[0065] In this embodiment, based on the configuration of the qubit and the readout coupling ports in the readout coupling port configuration layout, when adjusting the specifications of the readout coupling ports in the readout coupling port configuration layout, the lengths or widths of different regions of the readout coupling ports can be adjusted. In some alternative implementation manners of this embodiment, the readout coupling ports include: a first coupling port in a finger-like shape, and the first coupling port includes: a first finger portion parallel to the length direction of the capacitive arm of the qubit, and the capacitive arm is used to couple with the readout coupling port. In response to detecting that the coupling strength to be measured does not meet the preset conditions, adjusting the specifications of the readout coupling ports in the readout coupling port configuration layout, the obtained new readout coupling port configuration layout includes:

[0066] In response to the difference between the coupling strength to be measured and the target coupling strength being greater than the preset strength value, the length of the first finger portion is reduced by a first preset value to obtain a new readout coupling port configuration layout; in response to the difference between the target coupling strength and the coupling strength to be measured being greater than the preset strength value, the length of the first finger portion is increased by a first preset value to obtain a new readout coupling port configuration layout.

[0067] As Figure 3 In, the readout coupling port is a first coupling port in a finger-like shape, and the first coupling port includes a first finger portion, and the length of the first finger portion is a. Further, in Figure 3 In, the first coupling port may further include: a second finger portion parallel to the width direction of the capacitive arm of the qubit, and the width of the second finger portion is b. By adjusting the width of the second finger portion, a new readout coupling port configuration can also be obtained.

[0068] In this alternative implementation manner, based on the comparison between the coupling strength to be measured and the target coupling strength, the readout coupling port configuration layout is iterated.

[0069] In this alternative implementation manner, the first preset value and the preset strength value can be set based on the design accuracy. For example, the preset strength value is 10%, and the first preset value is 10 um.

[0070] The method for adjusting the specifications of the readout coupling port provided by this alternative implementation can quickly and conveniently make the obtained new coupling port approach the second target frequency when the readout coupling port is in a interdigital configuration and the readout coupling port is coupled to the capacitive arm of the qubit, ensuring the efficiency of the layout adjustment of the readout coupling port configuration.

[0071] In some alternative implementations of this embodiment, the readout coupling port includes: a second interdigital coupling port, and the second coupling port includes: a second finger parallel to the width direction of the capacitive arm of the qubit. The capacitive arm is used to couple with the readout coupling port. In response to detecting that the measured coupling strength does not meet the preset condition with the target coupling strength, the specifications of the readout coupling port in the layout of the readout coupling port configuration are adjusted to obtain a new layout of the readout coupling port configuration, including: in response to the difference between the measured coupling strength and the target coupling strength being greater than the preset strength value, reducing the width of the second finger by a second preset value to obtain a new layout of the readout coupling port configuration; in response to the difference between the target coupling strength and the measured coupling strength being greater than the preset strength value, increasing the width of the second finger by a second preset value to obtain a new layout of the readout coupling port configuration. In this embodiment, the second preset value has nothing to do with the second preset value.

[0072] The method for adjusting the specifications of the readout coupling port provided by this alternative implementation can quickly and conveniently make the obtained new coupling port approach the second target frequency when the readout coupling port is in a interdigital configuration and the readout coupling port is coupled to the capacitive arm of the qubit, ensuring the efficiency of the layout adjustment of the readout coupling port configuration.

[0073] For the above embodiment, in order to verify the reliability of the generated full layout, in another embodiment of the present disclosure, the above superconducting qubit coupling method may further include: performing electromagnetic simulation on the full layout to obtain the self-capacitance of the qubit and the mutual capacitance of the coupling between the qubit and the target readout cavity; calculating the calculated coupling strength based on the self-capacitance of the qubit, the mutual coupling capacitance, the first target frequency, and the second target frequency; and determining that the full layout is correct in response to detecting that the calculated coupling strength meets the preset condition with the target coupling strength.

[0074] Optionally, in response to detecting that the calculated coupling strength does not meet the preset condition with the target coupling strength, adjust the distance between the qubit and the readout coupling port in the layout of the readout coupling port configuration to obtain a new layout of the readout coupling port configuration; calculate the measured coupling strength based on the new layout of the readout coupling port configuration, and generate a new full layout when the measured coupling strength meets the preset condition with the target coupling strength.

[0075] Optionally, in response to detecting that the calculated coupling strength does not meet the preset condition with the target coupling strength, adjust the specifications of the read coupling ports in the layout of the read coupling port configuration to obtain a new layout of the read coupling port configuration; based on the new layout of the read coupling port configuration, calculate the coupling strength to be measured, and when the coupling strength to be measured meets the preset condition with the target coupling strength, generate a new complete layout.

[0076] In this embodiment, calculating the coupling strength to be measured based on the new layout of the read coupling port configuration includes: inputting the new layout of the read coupling port configuration and the size parameters between the qubit and the read coupling ports into simulation software to obtain the simulated capacitance and simulated frequency; calculating the coupling strength to be measured based on the simulated capacitance and the simulated frequency.

[0077] For the superconducting qubit coupling method provided in this embodiment, perform electromagnetic simulation on the complete layout, calculate the calculated coupling strength, and in response to the calculated coupling strength meeting the preset condition with the target coupling strength, determine that the complete layout is correct. The complete layout can be applied to the actual production of quantum chips, improving the reliability of the target read cavity.

[0078] In some alternative implementation manners of this embodiment, calculating the calculated coupling strength based on the self-capacitance of the qubit, the coupling mutual capacitance, the first target frequency, and the second target frequency includes:

[0079] Substitute the self-capacitance of the qubit, the coupling mutual capacitance, the first target frequency, and the second target frequency into the impedance coupling relation of the read cavity to obtain the calculated coupling strength; the impedance coupling relation of the read cavity is used to characterize the corresponding relationship between the coupling mutual capacitance, the self-capacitance of the qubit, the standard impedance, the first target frequency, the second target frequency, and the calculated coupling strength.

[0080] Model the chip layout using an equivalent circuit. The coupling strength between the qubit and the read cavity can be as shown in Equation (2):

[0081]

[0082] In Equation (2), C q and C r are respectively the self-capacitances of the qubit and the read cavity, and C qr is the coupling mutual capacitance between the qubit and the read cavity. ω q and ω r are respectively the frequencies of the qubit and the read cavity. After designing the initial complete layout of the qubit and the read cavity, performing electromagnetic simulation on the quantum chip layout can obtain the self-capacitance, mutual capacitance, and frequency information between the qubit and the read cavity, and substituting them into the above Equation (2) can calculate the coupling strength between the qubit and the read cavity.

[0083] The readout cavity is usually implemented using a quarter coplanar waveguide with a standard impedance (Z0) of 50 ohms, i.e.,

[0084]

[0085] In Equation (3), Z r is the impedance of the readout cavity, and Z0 = 50 ohm is the standard impedance. Substituting this relationship into Equation (2), we get

[0086]

[0087] In Equation (4), the impedance Z r of the readout cavity is replaced with the standard 50-ohm impedance Z0. It can be seen from the above Equation (4) that the readout coupling strength is no longer explicitly related to the self-capacitance C r of the readout cavity. In fact, as long as the ratio of the width of the center conductor of the coplanar waveguide to the width of either side of the two metal grounds is reasonably designed, the impedance of the readout cavity can be kept uniformly at 50 ohms. In addition, the coupling mutual capacitance between the readout cavity and the qubit is only related to the configuration of the adjacent coupling ports. Therefore, without the complete layout of the readout cavity, only the layout of the coupling port configuration between the readout cavity and the qubit (such as Figure 2 ) needs to be simulated to obtain the coupling capacitance C qr and the qubit self-capacitance C q . Together with the preset first target frequency of the qubit and the second target frequency of the readout cavity, the coupling strength between the qubit and the readout cavity can be calculated using Equation (4).

[0088] In this embodiment, the impedance coupling relationship of the readout cavity can be calculated using the relationship shown in Equation (4) (at this time, the readout cavity corresponding to Equation (4) is the target readout cavity), and the calculated coupling strength corresponding to the coupling strength between the qubit and the readout cavity can be obtained.

[0089] The method for obtaining the calculated coupling strength provided in this embodiment, when the impedance of the target readout cavity is the standard ohm impedance and the target readout cavity and the qubit are directly coupled to form a dispersive coupling relationship (the frequency difference between the qubit and the target readout cavity is much larger than the coupling strength between them), the calculated coupling strength between the operator qubit and the target readout cavity can be calculated through the impedance coupling relationship of the readout cavity. It provides a reliable calculation method for the calculation of the coupling strength.

[0090] In some alternative implementation manners of this embodiment, the above determination of the target coupling strength between the target readout cavity and the qubit, the first target frequency of the qubit, and the second target frequency of the target readout cavity includes: obtaining the preset first target frequency and target coupling strength of the qubit; calculating the second target frequency based on the first target frequency and the target coupling strength.

[0091] In this embodiment, the above-mentioned second target frequency can be a value. The above-mentioned calculation of the second target frequency based on the first target frequency and the target coupling strength includes: determining the first magnitude of the target coupling strength and setting a fixed frequency based on the principle of dispersion coupling conditions, wherein the magnitude of the set fixed frequency is greater than the magnitude of the target coupling strength; increasing the first target frequency by the set frequency to obtain the second target frequency.

[0092] For example, in a specific example, if the first order is MHz, the order of the fixed frequency is set to GHz, and the fixed frequency may be a value greater than 1 GHz.

[0093] Optionally, the second target frequency can also be multiple values. The second target frequency is calculated based on the first target frequency and the target coupling strength, including: determining the first magnitude and the incremental frequency interval of the target coupling strength based on the principle of dispersion coupling conditions, wherein the magnitude of the incremental frequency interval is the same as the first magnitude, and the value of the incremental frequency interval is greater than the target coupling strength; subtracting the set frequency value from the first target frequency to obtain the base frequency, and increasing the base frequency by a set number of incremental frequency intervals in sequence, wherein each increase in the base frequency by an incremental frequency interval is a target frequency, and the final value of the base frequency increased by a set number of incremental frequency intervals is less than the magnitude of the first target frequency.

[0094] In this embodiment, when the frequency difference between the quantum bit and the target reading cavity is much larger than the coupling strength between the two, the target coupling strength can be obtained by accurately designing the coupling port between the reading cavity and the quantum bit. Based on the first target frequency and the target coupling strength, the second target frequency is calculated, which provides a reliable implementation method for obtaining the second target frequency.

[0095] In some optional implementations of the present embodiment, the second target frequency is multiple, and initializing the read coupling port configuration layout based on the configuration of the quantum bit and the relative position of the quantum bit and the target reading cavity includes: determining multiple read coupling ports based on the multiple second target frequencies; initializing the read coupling port configuration layout corresponding to the multiple read coupling ports based on the configuration of the quantum bit and the relative position of the quantum bit and the target reading cavity at the multiple second target frequencies; calculating the coupling strength to be measured between the quantum bit and the read coupling port based on the read coupling port configuration layout, the first target frequency, and the second target frequency includes: obtaining an intermediate frequency based on the multiple second target frequencies; calculating the coupling strength to be measured between the quantum bit and the read coupling port based on the read coupling port configuration layout corresponding to the multiple read coupling ports, the first target frequency, and the intermediate frequency.

[0096] In this alternative implementation manner, obtaining the intermediate frequency based on the multiple second target frequencies includes: averaging the multiple second target frequencies to obtain the intermediate frequency.

[0097] Then, calculating the coupling strength to be measured between the qubit and the readout coupling port based on the readout coupling port configuration layout, the first target frequency, and the second target frequencies includes: using the intermediate frequency as the second target frequency, and calculating the coupling strength to be measured between the qubit and the readout coupling port based on the readout coupling port configuration layout corresponding to multiple readout coupling ports, the first target frequency, and the second target frequencies; wherein, the coupling strength to be measured in this embodiment can be used as the coupling strength between each readout coupling port in the multiple readout coupling ports and the readout coupling port configuration layout of the qubit.

[0098] In this embodiment, for the second target frequency of each readout cavity among the multiple second target frequencies, in response to detecting that the coupling strength to be measured satisfies a preset condition with the target coupling strength, based on this second target frequency and the readout coupling port configuration layout, a complete layout including the qubit and the target readout cavity is generated.

[0099] The method for initializing the readout coupling port configuration layout provided in this embodiment generates the readout coupling port configuration layouts at multiple second target frequencies simultaneously, providing a reliable implementation basis for generating multiple target readout cavities simultaneously. For a superconducting quantum chip containing multiple groups of different readout cavities, the solution of the present disclosure only requires one design of the readout coupling port to complete the design of multiple groups of different readout cavities.

[0100] To verify the effect of the solution of the present disclosure, the readout cavity coupling port design solution proposed in the present disclosure is applied to the layout design of a superconducting quantum chip with 6 groups of readout cavities. Under the process framework proposed in the solution of the present disclosure, a readout cavity layout that meets the requirements and has high iteration efficiency is accurately designed, verifying the effectiveness and advantages of the solution of the present disclosure. The specific steps are as follows:

[0101] The first step: Determine the target frequency and readout coupling strength of the readout cavity.

[0102] In the superconducting quantum chip design solution, the qubit frequency is set to 6.5 GHz. On the premise of satisfying dispersive coupling, the target frequencies of 6 groups of readout cavities are determined to be 4.86, 4.94, 5.02, 5.10, 5.18, 5.26 GHz (frequency interval 80 MHz), and the target coupling strength between the readout cavity and the qubit is set to 38 MHz.

[0103] The second step: Initialize the readout coupling port layout.

[0104] Based on the layout of qubits and the relative positions of the readout cavity and qubits, design a preliminary layout of the readout coupling port configuration. Considering that the frequencies of the six groups of readout cavities do not differ much, the six groups of readout coupling ports adopt a unified interdigital coupling configuration (such as Figure 2 ), which can meet the design requirements.

[0105] Third and fourth steps: Iterate the layout of the readout coupling port, simulate and calculate the coupling strength.

[0106] After multiple iterations in the third and fourth steps, perform electromagnetic simulation on the final layout of the readout coupling port configuration to obtain the self-capacitance C q = 65 fF of the qubit, and the mutual capacitance C qr = 2.72 fF between the qubit and the readout cavity. The qubit frequency ω q = 6.5 GHz, and the readout cavity frequency ω r takes the intermediate frequency of 5 GHz. Substituting into Equation (4) can calculate the coupling strength g = 38.1 MHz between the qubit and the readout cavity, which is very close to the target coupling strength and meets the requirements.

[0107] Fifth step: Verify the complete layout.

[0108] According to the target frequency of the readout cavity, complete the designed readout coupling port to form a complete layout of the qubit and the readout cavity. The schematic diagram is as shown in Figure 3 . Perform electromagnetic simulation on this complete layout, and use multiple methods to cross-verify the coupling strength between the qubit and the readout cavity based on the simulation data. The results are shown in Table 1.

[0109] Table 1

[0110]

[0111] In Table 1, Layouts 1, 2, and 3 are three groups of qubit configurations, and their corresponding readout cavity frequencies are as shown in Table 1. Using three different simulation verification methods: resonance sweep frequency, equivalent circuit, and iEPR (inductance energy participation ratio, based on the theory of inductance-based energy partitioning) method, cross-verify the coupling strength between the qubit and the readout cavity. Among them, the resonance sweep frequency method tunes the qubit frequency to resonance at the readout cavity frequency and calculates the coupling strength using the frequency difference between the two devices; the equivalent circuit method uses the self-capacitance and mutual capacitance information of the devices to perform equivalent circuit modeling and calculates the coupling strength using Equation (1) mentioned above; the iEPR method calculates the coupling strength between the devices using the electromagnetic field distribution around the devices. The principles of the three methods are all different, but their calculation results of the coupling strength between the qubit and the readout cavity under the complete layout are all very close to the target coupling strength of 38 MHz, thus verifying the effectiveness of the proposed solution in this disclosure.

[0112] Using the solution of the present disclosure, the layout design of a superconducting quantum chip with 6 groups of readout cavities is completed. After simulation verification, the coupling strength between the qubit and the readout cavity meets the design requirements. Therefore, the solution of the present disclosure can improve the design efficiency of superconducting quantum chips and has guiding significance for the design, simulation, and iteration of superconducting quantum chips.

[0113] In some alternative implementation manners of this embodiment, calculating the to-be-detected coupling strength between the qubit and the read coupling port based on the layout of the read coupling port configuration, the first target frequency, and the second target frequency includes:

[0114] Performing electromagnetic simulation on the layout of the read coupling port configuration to obtain the self-capacitance of the qubit and the mutual capacitance between the qubit and the read coupling port;

[0115] Substituting the self-capacitance of the qubit, the mutual capacitance of the ports, the first target frequency, and the second target frequency into the port impedance coupling relation formula to obtain the to-be-detected coupling strength;

[0116] The port impedance coupling relation formula is used to characterize the corresponding relationship between the mutual capacitance of the ports, the self-capacitance of the qubit, the standard impedance, the first target frequency, the second target frequency, and the to-be-detected coupling strength.

[0117] In this alternative implementation manner, the port impedance coupling relation formula can be calculated using the relation formula shown in Equation (4) (at this time, the readout cavity corresponding to Equation (4) is the read coupling port), and the to-be-detected coupling strength corresponding to the coupling strength between the qubit and the readout cavity can be obtained.

[0118] The superconducting qubit coupling method provided in this embodiment performs electromagnetic simulation on the layout of the read coupling port configuration, calculates the to-be-detected coupling strength, and determines that the configuration of the read coupling port and the qubit is correct in response to the to-be-detected coupling strength meeting the preset condition with the target coupling strength, improving the reliability of the obtained target readout cavity.

[0119] In some alternative implementation manners of this embodiment, in response to detecting that the to-be-detected coupling strength meets the preset condition with the target coupling strength, generating a complete layout including the qubit and the target readout cavity based on the second target frequency and the layout of the read coupling port configuration includes:

[0120] In response to detecting that the to-be-detected coupling strength meets the preset condition with the target coupling strength, completing the read coupling port in the layout of the read coupling port configuration to generate a complete layout including the qubit and the target readout cavity.

[0121] In this embodiment, the read coupling port can be complemented based on the positional relationship between the qubit and the target read cavity in the complete layout, so that the complemented read coupling port forms the target read cavity. It should be noted that the target read cavity is usually implemented by a quarter coplanar waveguide with a standard impedance. In order to ensure the generation effect of the target read cavity, it is necessary to reasonably design the ratio of the width of the central conductor of the coplanar waveguide to the width of the metal ground on both sides. For example, if the target read cavity is a 50-ohm coplanar waveguide, when complementing the read coupling port, it is necessary to ensure that the ratio of the width of the central conductor of the coplanar waveguide to the width of any one side of the metal ground on both sides is 2 / 1.

[0122] The complete layout of generating a qubit and a target read cavity provided in this embodiment only needs to focus on the layout of the read coupling port configuration between the target read cavity and the qubit, which accelerates the design and simulation processes of the entire read coupling port; when generating the target read cavity, only the read coupling port is complemented, which simplifies the simulation process of the target read cavity and improves the design efficiency of the target read cavity.

[0123] Further referring to Figure 5 , as an implementation of the methods shown in the above figures, the present disclosure provides an embodiment of a superconducting qubit coupling device. This device embodiment corresponds to the Figure 1 method embodiment shown, and this device can be specifically applied to various electronic devices.

[0124] As shown in Figure 5 , the superconducting qubit coupling device 500 provided in this embodiment includes: a determination unit 501, an initialization unit 502, a calculation unit 503, and a generation unit 504. Among them, the above determination unit 501 can be configured to determine the target coupling strength between the target read cavity and the qubit, the first target frequency of the qubit, and the second target frequency of the target read cavity. The above initialization unit 502 can be configured to initialize the layout of the read coupling port configuration based on the configuration of the qubit and the relative position between the qubit and the target read cavity. The layout of the read coupling port configuration is a layout used to characterize the positional relationship between the read coupling ports of the qubit and the target read cavity. The above calculation unit 503 can be configured to calculate the to-be-detected coupling strength between the qubit and the read coupling port based on the layout of the read coupling port configuration, the first target frequency, and the second target frequency. The above generation unit 504 can be configured to, in response to detecting that the to-be-detected coupling strength satisfies a preset condition with the target coupling strength, generate a complete layout including the qubit and the target read cavity based on the second target frequency and the layout of the read coupling port configuration.

[0125] In this embodiment, in the superconducting qubit coupling device 500: the specific processing of the determination unit 501, the initialization unit 502, the calculation unit 503, and the generation unit 504 and the technical effects brought by them can be respectively referred toFigure 1 Regarding the relevant descriptions of steps 101, 102, 103, and 104 in the corresponding embodiment, they will not be elaborated here.

[0126] In some alternative implementation manners of this embodiment, the above-mentioned device further includes: a pitch adjustment unit (not shown in the figure), and the pitch adjustment unit is configured to, in response to detecting that the measured coupling strength and the target coupling strength do not meet the preset conditions, adjust the pitch between the read coupling port and the qubit in the read coupling port configuration layout to obtain a new read coupling port configuration layout; replace the read coupling port configuration layout with the new read coupling port configuration layout; continue to control the operation of the calculation unit 503 until it is detected that the measured coupling strength and the target coupling strength meet the preset conditions, and then control the operation of the generation unit 504.

[0127] In some alternative implementation manners of this embodiment, the above-mentioned device further includes: a specification adjustment unit (not shown in the figure), and the specification adjustment unit can be configured to, in response to detecting that the measured coupling strength and the target coupling strength do not meet the preset conditions, adjust the specification of the read coupling port in the read coupling port configuration layout to obtain a new read coupling port configuration layout; replace the read coupling port configuration layout with the new read coupling port configuration layout; continue to control the operation of the calculation unit 503 until it is detected that the measured coupling strength and the target coupling strength meet the preset conditions, and then control the operation of the generation unit 504.

[0128] In some alternative implementation manners of this embodiment, the above-mentioned read coupling port includes: a first coupling port in a finger shape, and the first coupling port includes: a first finger portion parallel to the length direction of the capacitive arm of the qubit, and the capacitive arm is used to couple with the read coupling port. The specification adjustment unit is further configured to: in response to the difference between the measured coupling strength and the target coupling strength being greater than the preset strength value, reduce the length of the first finger portion by a first preset value to obtain a new read coupling port configuration layout; in response to the difference between the target coupling strength and the measured coupling strength being greater than the preset strength value, increase the length of the first finger portion by a first preset value to obtain a new read coupling port configuration layout.

[0129] In some alternative implementation manners of this embodiment, the above-mentioned read coupling port includes: a second coupling port in a finger shape, and the second coupling port includes: a second finger portion parallel to the width direction of the capacitive arm of the qubit, and the capacitive arm is used to couple with the read coupling port. The specification adjustment unit is further configured to: in response to the difference between the measured coupling strength and the target coupling strength being greater than the preset strength value, reduce the width of the second finger portion by a second preset value to obtain a new read coupling port configuration layout; in response to the difference between the target coupling strength and the measured coupling strength being greater than the preset strength value, increase the width of the second finger portion by a second preset value to obtain a new read coupling port configuration layout.

[0130] In some alternative implementation manners of this embodiment, the above device further includes: a verification unit (not shown in the figure). Among them, the above verification unit can be configured to perform electromagnetic simulation on the full version diagram to obtain the self-capacitance of the qubit and the mutual capacitance of the coupling between the qubit and the target read cavity; calculate the calculated coupling strength based on the self-capacitance of the qubit, the mutual capacitance of the coupling, the first target frequency, and the second target frequency; and determine that the full version diagram is correct in response to detecting that the calculated coupling strength meets a preset condition.

[0131] In some alternative implementation manners of this embodiment, the above verification unit is further configured to: substitute the self-capacitance of the qubit, the mutual capacitance of the coupling, the first target frequency, and the second target frequency into the read cavity impedance coupling relation formula to obtain the calculated coupling strength; the read cavity impedance coupling relation formula is used to characterize the corresponding relationship between the mutual capacitance of the coupling, the self-capacitance of the qubit, the standard impedance, the first target frequency, the second target frequency, and the calculated coupling strength.

[0132] In some alternative implementation manners of this embodiment, the above determination unit 501 is further configured to: obtain the first target frequency and the target coupling strength of the qubit set in advance; calculate the second target frequency based on the first target frequency and the target coupling strength.

[0133] In some alternative implementation manners of this embodiment, there are multiple second target frequencies. The initialization unit 502 is further configured to: determine multiple read coupling ports based on the multiple second target frequencies; initialize the read coupling port configuration diagram corresponding to the multiple read coupling ports based on the configuration of the qubit and the relative positions of the qubit and the target read cavity at the multiple second target frequencies; the calculation unit 503 is further configured to: obtain an intermediate frequency based on the multiple second target frequencies; calculate the to-be-detected coupling strength between the qubit and the read coupling port based on the read coupling port configuration diagram corresponding to the multiple read coupling ports, the first target frequency, and the intermediate frequency.

[0134] In some alternative implementation manners of this embodiment, the above calculation unit 503 is further configured to: perform electromagnetic simulation on the read coupling port configuration diagram to obtain the self-capacitance of the qubit and the port mutual capacitance between the qubit and the read coupling port; substitute the self-capacitance of the qubit, the port mutual capacitance, the first target frequency, and the second target frequency into the port impedance coupling relation formula to obtain the to-be-detected coupling strength; the port impedance coupling relation formula is used to characterize the corresponding relationship between the port mutual capacitance, the self-capacitance of the qubit, the standard impedance, the first target frequency, the second target frequency, and the to-be-detected coupling strength.

[0135] In some alternative implementation manners of this embodiment, the above-mentioned generating unit 504 is further configured to: in response to detecting that the coupling strength to be measured and the target coupling strength meet a preset condition, complete the read coupling port in the read coupling port configuration layout diagram, and generate a complete layout diagram including the qubit and the target read cavity.

[0136] For the superconducting qubit coupling device provided by the embodiment of the present disclosure, first, the determining unit 501 determines the target coupling strength between the target read cavity and the qubit, the first target frequency of the qubit, and the second target frequency of the target read cavity; secondly, the initializing unit 502 initializes the read coupling port configuration layout diagram based on the configuration of the qubit and the relative position between the qubit and the target read cavity, and the read coupling port configuration layout diagram is a layout diagram used to characterize the positional relationship between the qubit and the read coupling port of the target read cavity; thirdly, the calculating unit 503 calculates the coupling strength to be measured between the qubit and the read coupling port based on the read coupling port configuration layout diagram, the first target frequency, and the second target frequency; finally, in response to detecting that the coupling strength to be measured and the target coupling strength meet the preset condition, the generating unit 504 generates a complete layout diagram including the qubit and the target read cavity based on the second target frequency and the read coupling port configuration layout diagram. The present disclosure only needs to focus on the read coupling port configuration layout diagram reflecting the positional relationship between the qubit and the read coupling port, and can calculate the coupling strength to be measured without completely designing the layout diagram of the entire read cavity, which greatly improves the design efficiency of the read cavity.

[0137] According to the embodiment of the present disclosure, the present disclosure also provides an electronic device, a readable storage medium, and a computer program product.

[0138] Figure 6 FIG. shows a schematic block diagram of an exemplary electronic device 600 that can be used to implement the embodiments of the present disclosure. The electronic device is intended to represent various forms of digital computers, such as, a laptop computer, a desktop computer, a workbench, a personal digital assistant, a server, a blade server, a mainframe computer, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as, a personal digital processor, a cellular phone, a smart phone, a wearable device, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0139] As Figure 6As shown, device 600 includes a computing unit 601 which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 602 or a computer program loaded from a storage unit 608 into a random access memory (RAM) 603. In the RAM 603, various programs and data required for the operation of device 600 can also be stored. The computing unit 601, ROM 602, and RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0140] Multiple components in device 600 are connected to the I / O interface 605, including: an input unit 606, such as a keyboard, a mouse, etc.; an output unit 607, such as various types of displays, speakers, etc.; a storage unit 608, such as a magnetic disk, an optical disc, etc.; and a communication unit 609, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 609 allows device 600 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0141] The computing unit 601 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 601 include but are not limited to a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The computing unit 601 executes the various methods and processes described above, such as the superconducting qubit coupling method. For example, in some embodiments, the superconducting qubit coupling method can be implemented as a computer software program which is tangibly contained in a machine-readable medium, such as the storage unit 608. In some embodiments, part or all of the computer program can be loaded and / or installed onto device 600 via the ROM 602 and / or the communication unit 609. When the computer program is loaded into the RAM 603 and executed by the computing unit 601, one or more steps of the superconducting qubit coupling method described above can be executed. Alternatively, in other embodiments, the computing unit 601 can be configured to execute the superconducting qubit coupling method by any other appropriate means (e.g., by means of firmware).

[0142] The various embodiments of the systems and techniques described above in this specification can be implemented in digital electronic circuitry, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on a chip (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: being implemented in one or more computer programs that are executable and / or interpretable on a programmable system including at least one programmable processor, which may be a special-purpose or general-purpose programmable processor that receives data and instructions from, and transmits data and instructions to, a storage system, at least one input device, and at least one output device.

[0143] The program code for implementing the methods of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable superconducting qubit coupling device, such that the program codes, when executed by the processor or controller, cause the functions / operations specified in the flowchart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partly on the machine, as a stand-alone software package partly on the machine and partly on a remote machine, or entirely on the remote machine or server.

[0144] In the context of the present disclosure, a machine-readable medium can be a tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0145] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and a pointing device (e.g., a mouse or a trackball) through which the user can provide input to the computer. Other kinds of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and the input received from the user can be in any form (including acoustic input, speech input, or tactile input).

[0146] The systems and techniques described herein can be implemented in a computing system including backend components (e.g., as a data server), or a computing system including middleware components (e.g., an application server), or a computing system including frontend components (e.g., a user computer having a graphical user interface or a web browser through which the user can interact with an implementation of the systems and techniques described herein), or a computing system including any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected by digital data communication in any form or medium (e.g., a communication network). Examples of communication networks include: local area network (LAN), wide area network (WAN), and the Internet.

[0147] A computer system can include a client and a server. The client and the server are generally remote from each other and typically interact through a communication network. The client - server relationship is created by computer programs running on the respective computers and having a client - server relationship with each other.

[0148] In the technical solutions of the present disclosure, the acquisition, storage, and application of the user's personal information involved all comply with the provisions of relevant laws and regulations and do not violate public order and good customs.

[0149] It should be understood that various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps recited in the present disclosure can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved, and no limitation is made herein.

[0150] The above - mentioned specific embodiments do not constitute a limitation on the protection scope of the present disclosure. Those skilled in the art should understand that various modifications, combinations, sub - combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present disclosure should be included within the protection scope of the present disclosure.

Claims

1. A superconducting qubit coupling method, the method comprising: Determining a target coupling strength between a target readout cavity and a qubit, a first target frequency of the qubit, and a second target frequency of the target readout cavity; Initializing a readout coupling port configuration layout based on the configuration of the qubit and the relative position between the qubit and the target readout cavity, the readout coupling port configuration layout being a layout for characterizing the positional relationship between the qubit and the readout coupling ports of the target readout cavity; Calculating a to-be-detected coupling strength between the qubit and the readout coupling port based on the readout coupling port configuration layout, the first target frequency, and the second target frequency; In response to detecting that the to-be-detected coupling strength and the target coupling strength meet a preset condition, generating a complete layout including the qubit and the target readout cavity based on the second target frequency and the readout coupling port configuration layout.

2. The method according to claim 1, the method further comprising: In response to detecting that the to-be-detected coupling strength and the target coupling strength do not meet the preset condition, adjusting the distance between the readout coupling port and the qubit in the readout coupling port configuration layout to obtain a new readout coupling port configuration layout; Replacing the readout coupling port configuration layout with the new readout coupling port configuration layout; Continuing to calculate the to-be-detected coupling strength between the qubit and the readout coupling port based on the readout coupling port configuration layout, the first target frequency, and the second target frequency until it is detected that the to-be-detected coupling strength and the target coupling strength meet the preset condition.

3. The method according to claim 1, the method further comprising: In response to detecting that the to-be-detected coupling strength and the target coupling strength do not meet the preset condition, adjusting the specifications of the readout coupling port in the readout coupling port configuration layout to obtain a new readout coupling port configuration layout; Replacing the readout coupling port configuration layout with the new readout coupling port configuration layout; Continuing to calculate the to-be-detected coupling strength between the qubit and the readout coupling port based on the readout coupling port configuration layout, the first target frequency, and the second target frequency until it is detected that the to-be-detected coupling strength and the target coupling strength meet the preset condition.

4. The method according to claim 3, wherein, The readout coupling port includes: a first coupling port in a finger-like shape, the first coupling port including: a first finger portion parallel to the length direction of the capacitive arm of the qubit, the capacitive arm being used to couple with the readout coupling port, and in response to detecting that the to-be-detected coupling strength and the target coupling strength do not meet the preset condition, adjusting the specifications of the readout coupling port in the readout coupling port configuration layout to obtain a new readout coupling port configuration layout includes: In response to the difference between the to-be-detected coupling strength and the target coupling strength being greater than a preset strength value, reducing the length of the first finger portion by a first preset value to obtain a new readout coupling port configuration layout; In response to the difference between the target coupling strength and the measured coupling strength being greater than the preset strength value, increase the length of the first finger portion by the first preset value to obtain a new layout of the read coupling port configuration.

5. The method according to claim 3, wherein The read coupling port includes: a second coupling port in a finger-like shape, and the second coupling port includes: a second finger portion parallel to the width direction of the capacitive arm of the qubit, and the capacitive arm is used to couple with the read coupling port. The adjusting the specification of the read coupling port in the layout of the read coupling port configuration in response to detecting that the measured coupling strength and the target coupling strength do not meet the preset conditions to obtain a new layout of the read coupling port configuration includes: In response to the difference between the measured coupling strength and the target coupling strength being greater than the preset strength value, decrease the width of the second finger portion by a second preset value to obtain a new layout of the read coupling port configuration; In response to the difference between the target coupling strength and the measured coupling strength being greater than the preset strength value, increase the width of the second finger portion by the second preset value to obtain a new layout of the read coupling port configuration.

6. The method according to claim 1, wherein the method further includes: Performing electromagnetic simulation on the complete layout to obtain the self-capacitance of the qubit and the mutual coupling capacitance between the qubit and the target read cavity; Calculating a calculated coupling strength based on the self-capacitance of the qubit, the mutual coupling capacitance, the first target frequency, and the second target frequency; In response to detecting that the calculated coupling strength and the target coupling strength meet the preset conditions, determining that the complete layout is correct.

7. The method according to claim 6, wherein The calculating the calculated coupling strength based on the self-capacitance of the qubit, the mutual coupling capacitance, the first target frequency, and the second target frequency includes: Substituting the self-capacitance of the qubit, the mutual coupling capacitance, the first target frequency, and the second target frequency into the impedance coupling relationship of the read cavity to obtain the calculated coupling strength; The impedance coupling relationship of the read cavity is used to characterize the corresponding relationship between the mutual coupling capacitance, the self-capacitance of the qubit, the standard impedance, the first target frequency, the second target frequency, and the calculated coupling strength.

8. The method according to any one of claims 1-7, wherein, The determining the target coupling strength between the target read cavity and the qubit, the first target frequency of the qubit, and the second target frequency of the target read cavity includes: Obtaining the first target frequency and the target coupling strength of the qubit set in advance; Calculating a second target frequency based on the first target frequency and the target coupling strength.

9. The method according to any one of claims 1 to 7, wherein, There are multiple second target frequencies. The initializing the layout of the read coupling port configuration based on the configuration of the qubit and the relative position between the qubit and the target read cavity includes: Determining multiple read coupling ports based on the multiple second target frequencies; Initializing the layout of the read coupling port configuration corresponding to the multiple read coupling ports based on the configuration of the qubit and the relative position between the qubit and the target read cavity at the multiple second target frequencies; Calculating the coupling strength to be measured between the qubit and the readout coupling port based on the layout of the readout coupling port configuration, the first target frequency, and the second target frequency includes: Based on the multiple second target frequencies, an intermediate frequency is obtained; based on the layout of the readout coupling port configuration corresponding to the multiple readout coupling ports, the first target frequency, and the intermediate frequency, the coupling strength to be measured between the qubit and the readout coupling port is calculated.

10. The method according to any one of claims 1-7, wherein, Calculating the coupling strength to be measured between the qubit and the readout coupling port based on the layout of the readout coupling port configuration, the first target frequency, and the second target frequency includes: Performing electromagnetic simulation on the layout of the readout coupling port configuration to obtain the self-capacitance of the qubit and the mutual capacitance between the qubit and the readout coupling port; Substituting the self-capacitance of the qubit, the mutual capacitance of the ports, the first target frequency, and the second target frequency into the port impedance coupling relation to obtain the coupling strength to be measured; The port impedance coupling relation is used to characterize the corresponding relationship among the mutual capacitance of the ports, the self-capacitance of the qubit, the standard impedance, the first target frequency, the second target frequency, and the coupling strength to be measured.

11. The method according to any one of claims 1 to 7, wherein, Responding to detecting that the coupling strength to be measured and the target coupling strength satisfy a preset condition, generating a complete layout including the qubit and the target readout cavity based on the second target frequency and the layout of the readout coupling port configuration includes: Responding to detecting that the coupling strength to be measured and the target coupling strength satisfy a preset condition, completing the readout coupling port in the layout of the readout coupling port configuration to generate a complete layout including the qubit and the target readout cavity.

12. A superconducting qubit coupling device, the device includes: A determination unit configured to determine the target coupling strength between the target readout cavity and the qubit, the first target frequency of the qubit, and the second target frequency of the target readout cavity; An initialization unit configured to initialize the layout of the readout coupling port configuration based on the configuration of the qubit and the relative position between the qubit and the target readout cavity, where the layout of the readout coupling port configuration is a layout for characterizing the positional relationship between the readout coupling ports of the qubit and the target readout cavity; A calculation unit configured to calculate the coupling strength to be measured between the qubit and the readout coupling port based on the layout of the readout coupling port configuration, the first target frequency, and the second target frequency; A generation unit configured to respond to detecting that the coupling strength to be measured and the target coupling strength satisfy a preset condition, and generate a complete layout including the qubit and the target readout cavity based on the second target frequency and the layout of the readout coupling port configuration.

13. The device according to claim 12, the device further includes: The spacing adjustment unit is configured to, in response to detecting that the measured coupling strength and the target coupling strength do not meet the preset condition, adjust the spacing between the read coupling port and the qubit in the read coupling port configuration layout to obtain a new read coupling port configuration layout; replace the read coupling port configuration layout with the new read coupling port configuration layout; continue to control the computing unit to work until it is detected that the measured coupling strength and the target coupling strength meet the preset condition, and then control the generating unit to work.

14. The apparatus according to claim 12, wherein the apparatus further comprises: The specification adjustment unit is configured to, in response to detecting that the measured coupling strength and the target coupling strength do not meet the preset condition, adjust the specification of the read coupling port in the read coupling port configuration layout to obtain a new read coupling port configuration layout; replace the read coupling port configuration layout with the new read coupling port configuration layout; continue to control the computing unit to work until it is detected that the measured coupling strength and the target coupling strength meet the preset condition, and then control the generating unit to work.

15. The apparatus according to claim 14, wherein, The read coupling port includes: a first coupling port in a finger-like shape, and the first coupling port includes: a first finger portion parallel to the length direction of the capacitive arm of the qubit, and the capacitive arm is used to couple with the read coupling port. The specification adjustment unit is further configured to: in response to the difference between the measured coupling strength and the target coupling strength being greater than a preset strength value, reduce the length of the first finger portion by a first preset value to obtain a new read coupling port configuration layout; in response to the difference between the target coupling strength and the measured coupling strength being greater than the preset strength value, increase the length of the first finger portion by the first preset value to obtain a new read coupling port configuration layout.

16. The device according to claim 14, wherein, The read coupling port includes: a second coupling port in a finger-like shape, and the second coupling port includes: a second finger portion parallel to the width direction of the capacitive arm of the qubit, and the capacitive arm is used to couple with the read coupling port. The specification adjustment unit is further configured to: in response to the difference between the measured coupling strength and the target coupling strength being greater than a preset strength value, reduce the width of the second finger portion by a second preset value to obtain a new read coupling port configuration layout; in response to the difference between the target coupling strength and the measured coupling strength being greater than the preset strength value, increase the width of the second finger portion by the second preset value to obtain a new read coupling port configuration layout.

17. The apparatus according to claim 12, wherein the apparatus further comprises: The verification unit is configured to perform electromagnetic simulation on the complete layout to obtain the self-capacitance of the qubit and the mutual capacitance of the coupling between the qubit and the target read cavity; Based on the self-capacitance of the qubit, the mutual capacitance of the coupling, the first target frequency, and the second target frequency, calculate the calculated coupling strength; In response to detecting that the calculated coupling strength meets the preset condition with the target coupling strength, it is determined that the full version graph is correct.

18. The apparatus according to claim 17, wherein The verification unit is further configured to: substitute the qubit self-capacitance, the coupling mutual capacitance, the first target frequency, and the second target frequency into the read cavity impedance coupling relation formula to obtain the calculated coupling strength; The read cavity impedance coupling relation formula is used to characterize the corresponding relationship between the coupling mutual capacitance, the qubit self-capacitance, the standard impedance, the first target frequency, the second target frequency, and the calculated coupling strength.

19. The device according to any one of claims 12 - 18, wherein The determination unit is further configured to: obtain the first target frequency and the target coupling strength of the qubit set in advance; based on the first target frequency and the target coupling strength, calculate to obtain the second target frequency.

20. The device according to any one of claims 12-18, wherein, There are multiple second target frequencies, and the initialization unit is further configured to: determine multiple read coupling ports based on the multiple second target frequencies; Based on the configuration of the qubit and the relative positions of the qubit and the target read cavity at the multiple second target frequencies, initialize the read coupling port configuration layout corresponding to the multiple read coupling ports; The calculation unit is further configured to: obtain an intermediate frequency based on the multiple second target frequencies; based on the read coupling port configuration layout corresponding to the multiple read coupling ports, the first target frequency, and the intermediate frequency, calculate the to-be-detected coupling strength between the qubit and the read coupling port.

21. The device according to one of claims 12 - 18, wherein, The calculation unit is further configured to: perform electromagnetic simulation on the read coupling port configuration layout to obtain the qubit self-capacitance of the qubit and the port mutual capacitance between the qubit and the read coupling port; substitute the qubit self-capacitance, the port mutual capacitance, the first target frequency, and the second target frequency into the port impedance coupling relation formula to obtain the to-be-detected coupling strength; the port impedance coupling relation formula is used to characterize the corresponding relationship between the port mutual capacitance, the qubit self-capacitance, the standard impedance, the first target frequency, the second target frequency, and the to-be-detected coupling strength.

22. The device according to any one of claims 12-18, wherein, The generation unit is further configured to: in response to detecting that the to-be-detected coupling strength meets the preset condition with the target coupling strength, complete the read coupling ports in the read coupling port configuration layout to generate a full version graph including the qubit and the target read cavity.

23. An electronic device, characterized in that, Comprising: At least one processor; And A memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method according to any one of claims 1-11.

24. A non-transitory computer-readable storage medium storing computer instructions, characterized in that, The computer instructions are used to cause the computer to execute the method according to any one of claims 1-11.

25. A computer program product, comprising a computer program which, when executed by a processor, implements the method according to any one of claims 1-11.

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