A signal channel selection method and apparatus suitable for superconducting quantum computing

Abstract

The application provides a signal channel selection method and device suitable for superconducting quantum computing. The method comprises: for an input line, constructing n output lines, one output line being a signal channel; the output line comprises a capacitor and an illuminated superconducting line, one end of the capacitor being connected to the input line, the other end being connected to one end of the illuminated superconducting line and a load respectively, and the other end of the illuminated superconducting line being grounded; wherein for each output line, when the illuminated superconducting line is in a superconducting state, the output line is directly grounded, that is, the signal channel is closed, and a microwave signal input from the input line cannot be transmitted to the load through the signal channel; when the illuminated superconducting line is in a normal conductor state, the output line forms an RC high-pass filter, that is, the signal channel is an open channel, and the microwave signal input from the input line is transmitted to the load through the RC high-pass filter.

Description

Technical Field

[0001] This invention relates to the field of superconducting quantum computing technology, and in particular to a signal channel selection method and apparatus suitable for superconducting quantum computing. Background Technology

[0002] In recent years, superconducting quantum computing technology has developed rapidly and has become one of the most mature quantum computing technologies. Superconducting quantum computing chips need to operate in a dilution refrigerator to provide the extremely low temperature environment required for their operation. Due to cost and power constraints, the sample space in the dilution refrigerator is usually limited.

[0003] Manipulating and reading superconducting qubits generally requires transmission lines to transmit specific waveform microwave and DC signals generated by an external control system to the corresponding qubits, enabling operations such as qubit gate manipulation and reading. To reduce noise introduced during signal transmission, filters, attenuators, circulators, and other devices are typically added to the lines. These devices often need to be connected to the cold plates of each temperature layer of a dilution refrigerator to achieve rapid heat dissipation.

[0004] On the one hand, microwave (DC) signal transmission lines and related devices are expensive; generally, the cost of the measurement and control lines is comparable to that of a dilution refrigerator. On the other hand, the low integration of transmission lines and related devices limits the number of lines within a dilution refrigerator to approximately a thousand. Line multiplexing is one potential solution to this problem, but it typically requires a line selection device to manipulate specific qubits. Therefore, how to achieve signal channel selection still requires further research. Summary of the Invention

[0005] In order to achieve signal channel selection for the purpose of circuit multiplexing in superconducting quantum computing, this invention provides a signal channel selection method and apparatus suitable for superconducting quantum computing.

[0006] In a first aspect, the present invention provides a signal channel selection method suitable for superconducting quantum computing, applied to microwave signals, the method comprising: For one input line, n output lines are constructed for it, and one output line is a signal channel; the output line includes a capacitor and an illumination superconducting wire circuit. One end of the capacitor is connected to the input line, and the other end is connected to one end of the illumination superconducting wire circuit and the load respectively. The other end of the illumination superconducting wire circuit is grounded. For each output line, when the illumination superconducting circuit is in a superconducting state, the output line is directly grounded, meaning the signal channel is closed, and the microwave signal input from the input line cannot be transmitted to the load through this signal channel. When the illumination superconducting circuit is in a normal conductor state, the output line forms an RC high-pass filter, meaning the signal channel is open, and the microwave signal input from the input line is transmitted to the load through the RC high-pass filter. The cutoff frequency is... , R It is the resistance corresponding to the state of a normal conductor. C It is the capacitance value.

[0007] Secondly, the present invention provides a signal channel selection method suitable for superconducting quantum computing, applied to DC signals, the method comprising: For one input line, n output lines are constructed for it, and one output line is a signal channel; the output line includes a light-emitting superconducting wire circuit, one end of which is connected to the input line and the other end is grounded; For each output line, when the superconducting light-irradiated line is heated by light radiation, the output line is in a resisted state; otherwise, it is in an unresisted superconducting state, and the output line at this time is the DC signal channel. In this way, the DC signal channel selection function is realized by selectively heating the n output lines with light radiation.

[0008] Furthermore, the optical fiber is aligned with the illumination superconducting circuit, and then the optical fiber is connected to an external control laser line. Controllable illumination is achieved by adjusting the control laser line to provide or not provide optical signals.

[0009] Furthermore, the illumination superconducting circuit can adopt a two-dimensional nanoscale meandering circuit structure.

[0010] Thirdly, the present invention provides a signal channel selection device suitable for superconducting quantum computing, applied to microwave signals. The device includes: one input line and n output lines; one output line is a signal channel; the output line includes a capacitor and an illumination superconducting circuit, one end of the capacitor is connected to the input line, and the other end is connected to one end of the illumination superconducting circuit and a load, respectively, and the other end of the illumination superconducting circuit is grounded. For each output line, when the illumination superconducting circuit is in a superconducting state, the output line is directly grounded, meaning the signal channel is closed, and the microwave signal input from the input line cannot be transmitted to the load through this signal channel. When the illumination superconducting circuit is in a normal conductor state, the output line forms an RC high-pass filter, meaning the signal channel is open, and the microwave signal input from the input line is transmitted to the load through the RC high-pass filter. The cutoff frequency is... , R It is the resistance corresponding to the state of a normal conductor. C It is the capacitance value.

[0011] Fourthly, the present invention provides a signal channel selection device suitable for superconducting quantum computing, applied to DC signals. The device includes: one input line and n output lines; one output line is a signal channel; the output line includes an illumination superconducting circuit, one end of which is connected to the input line and the other end is grounded. For each output line, when the superconducting light-irradiated line is heated by light radiation, the output line is in a resisted state; otherwise, it is in an unresisted superconducting state, and the output line at this time is the DC signal channel. In this way, the DC signal channel selection function is realized by selectively heating the n output lines with light radiation.

[0012] Furthermore, the illumination superconducting circuit is equipped with an optical fiber aligned with it, and the optical fiber is connected to an external control laser.

[0013] Furthermore, the illumination superconducting circuit can adopt a two-dimensional nanoscale meandering circuit structure.

[0014] Furthermore, the signal channel selection device is implemented by etching a thin film of superconducting material on the surface of an insulating substrate using micro-nano fabrication technology.

[0015] The beneficial effects of this invention are: This invention proposes a method and apparatus for signal channel selection suitable for superconducting quantum computing. Utilizing the temperature dependence of the superconducting state of a superconducting material, the method alters the temperature of the superconducting material circuit by radiating optical signals, thereby achieving controllable switching between the superconducting state (zero resistance) and the ordinary conductor state (non-zero resistance) of the superconducting material circuit. Different circuit designs enable controllable selection of microwave or DC signal channels. This invention solves the problem of difficult reusability of control circuits in superconducting quantum computing. The related device can function as an independent channel selection device or be integrated into a superconducting quantum computing chip, which is of great significance for improving the integration of measurement and control circuits in superconducting quantum computing. Attached Figure Description

[0016] Figure 1 This is one of the schematic diagrams of a signal channel selection method and a corresponding signal channel selection device suitable for superconducting quantum computing provided in an embodiment of the present invention; Figure 2 This is the second schematic diagram of a signal channel selection method and corresponding signal channel selection device suitable for superconducting quantum computing, provided in an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0018] Example 1 like Figure 1 As shown, this embodiment of the invention provides a signal channel selection method suitable for superconducting quantum computing, applied to microwave signals, the method comprising: For one input line, n output lines are constructed for it, and one output line is a signal channel; the output line includes a capacitor and an illumination superconducting wire circuit. One end of the capacitor is connected to the input line, and the other end is connected to one end of the illumination superconducting wire circuit and the load respectively. The other end of the illumination superconducting wire circuit is grounded. For each output line, when the illumination superconducting circuit is in a superconducting state, the output line is directly grounded, meaning the signal channel is closed, and the microwave signal input from the input line cannot be transmitted to the load through this signal channel. When the illumination superconducting circuit is in a normal conductor state, the output line forms an RC high-pass filter, meaning the signal channel is open, and the microwave signal input from the input line is transmitted to the load through the RC high-pass filter. The cutoff frequency is... , R It is the resistance corresponding to the state of a normal conductor. C This refers to the capacitance value. For example, with a capacitance of 0.1mF and a resistance of 10Ω, the cutoff frequency is 0.16MHz, which is a pathway for superconducting quantum computing microwave signals. It should be noted that the capacitance value in each output line can be different.

[0019] One possible implementation involves using coupling technology to align optical fibers with the illumination superconducting circuit, and then connecting the optical fibers to external control lasers. Controllable illumination is achieved by adjusting the control lasers to provide or not provide optical signals. For an n-channel illumination superconducting circuit, optical fibers with n cores are used to align with the n illumination superconducting circuits respectively, and each of the n cores of the optical fiber is connected to one of the n external control lasers.

[0020] Taking the first output line as the microwave signal channel as an example, the corresponding controller is adjusted to output an optical signal. The optical signal then automatically shines through the optical fiber onto the corresponding superconducting light circuit. At this time, the superconducting light circuit switches from the superconducting state to the ordinary conductor state, forming a path.

[0021] In order to better convert the energy of light radiation into heat for the light-irradiated superconducting circuit, and thus realize the transition from the superconducting state to the ordinary conductor state, the light-irradiated superconducting circuit can be realized through two-dimensional structures such as nanoscale meandering circuits. Such designs also help to improve the resistance in the ordinary conductor state.

[0022] Example 2 like Figure 2 As shown, this embodiment of the invention provides a signal channel selection method suitable for superconducting quantum computing, applied to DC signals, the method comprising: For one input line, n output lines are constructed for it, and one output line is a signal channel; the output line includes a light-emitting superconducting wire circuit, one end of which is connected to the input line and the other end is grounded; For each output line, when the superconducting light-irradiated line is heated by light radiation, the output line is in a resisted state; otherwise, it is in an unresisted superconducting state, and the output line at this time is the DC signal channel. In this way, the DC signal channel selection function is realized by selectively heating the n output lines with light radiation.

[0023] One possible implementation is to align an optical fiber with an illumination superconducting circuit, and then connect the optical fiber to an external control laser line. Controllable illumination is achieved by adjusting the control laser line to provide or not provide an optical signal.

[0024] For example, when the first output line is selected as the DC signal channel, the irradiated superconducting lines 2 to n in the second to nth output lines can be heated by light. Then the second to nth output lines are in a state of resistance, and the first output line is in a state of unresisted superconductivity. Thus, the function of selecting the first output line as the DC signal channel is realized.

[0025] In order to better convert the energy of light radiation into heat for the light-irradiated superconducting circuit, and thus realize the transition from the superconducting state to the ordinary conductor state, the light-irradiated superconducting circuit can be realized through two-dimensional structures such as nanoscale meandering circuits. Such designs also help to improve the resistance in the ordinary conductor state.

[0026] Example 3 like Figure 1 As shown, this embodiment of the invention provides a signal channel selection device suitable for superconducting quantum computing, applied to microwave signals. The device includes: one input line and n output lines; one output line is a signal channel; the output line includes a capacitor and an illumination superconducting circuit, one end of the capacitor is connected to the input line, and the other end is connected to one end of the illumination superconducting circuit and a load, respectively, and the other end of the illumination superconducting circuit is grounded. For each output line, when the illumination superconducting circuit is in a superconducting state, the output line is directly grounded, meaning the signal channel is closed, and the microwave signal input from the input line cannot be transmitted to the load through this signal channel. When the illumination superconducting circuit is in a normal conductor state, the output line forms an RC high-pass filter, meaning the signal channel is open, and the microwave signal input from the input line is transmitted to the load through the RC high-pass filter. The cutoff frequency is... , R It is the resistance corresponding to the state of a normal conductor. C It is the capacitance value.

[0027] Specifically, the illuminated superconducting circuit is equipped with an optical fiber aligned with it, and the optical fiber is connected to an external control laser. The control laser provides an optical signal, which is transmitted through the optical fiber. The illuminated superconducting circuit aligned with the optical fiber is heated by the optical radiation, realizing the switching from a superconducting state to a normal conductor state.

[0028] In order to better convert the energy of light radiation into heat for the light-irradiated superconducting circuit, and thus realize the transition from the superconducting state to the ordinary conductor state, the light-irradiated superconducting circuit can be realized through two-dimensional structures such as nanoscale meandering circuits. Such designs also help to improve the resistance in the ordinary conductor state.

[0029] Example 4 like Figure 2 As shown, this embodiment of the invention provides a signal channel selection device suitable for superconducting quantum computing, applied to DC signals. The device includes: one input line and n output lines; one output line is a signal channel; the output line includes an illumination superconducting wire circuit, one end of which is connected to the input line and the other end is grounded. For each output line, when the superconducting light-irradiated line is heated by light radiation, the output line is in a resisted state; otherwise, it is in an unresisted superconducting state, and the output line at this time is the DC signal channel. In this way, the DC signal channel selection function is realized by selectively heating the n output lines with light radiation.

[0030] Specifically, the illuminated superconducting circuit is equipped with an optical fiber aligned with it, and the optical fiber is connected to an external control laser. The control laser provides an optical signal, which is transmitted through the optical fiber. The illuminated superconducting circuit aligned with the optical fiber is heated by the optical radiation, realizing the switching from a superconducting state to a normal conductor state.

[0031] In order to better convert the energy of light radiation into heat for the light-irradiated superconducting circuit, and thus realize the transition from the superconducting state to the ordinary conductor state, the light-irradiated superconducting circuit can be realized through two-dimensional structures such as nanoscale meandering circuits. Such designs also help to improve the resistance in the ordinary conductor state.

[0032] It is understandable that, similar to superconducting quantum computing chips, the signal channel selection device in the above embodiments can be implemented by etching a superconducting material thin film on the surface of an insulating substrate using micro-nano fabrication technology.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A signal channel selection method suitable for superconducting quantum computing, characterized in that, Applied to microwave signals, the method includes: For one input line, n output lines are constructed, each output line constituting a signal channel. Each output line includes a capacitor and an illumination superconducting circuit. One end of the capacitor is connected to the input line, and the other end is connected to one end of the illumination superconducting circuit and a load, respectively. The other end of the illumination superconducting circuit is grounded. The illumination superconducting circuit utilizes the temperature dependence of superconducting materials, using optical signal radiation to change the temperature of the superconducting material circuit, thereby achieving controllable switching between the superconducting state and the ordinary conductor state of the superconducting material circuit. An optical fiber is aligned with the illumination superconducting circuit, and then the optical fiber is connected to an external... The control laser is connected to the control laser line, and controllable illumination is achieved by adjusting the control laser to provide or not provide light signals. For each output line, when the illumination superconducting line is in a superconducting state, the output line is directly grounded, meaning the signal channel is closed, and the microwave signal input from the input line cannot be transmitted to the load through this signal channel. When the illumination superconducting line is in a normal conductor state, the output line forms an RC high-pass filter, meaning the signal channel is open, and the microwave signal input from the input line is transmitted to the load through the RC high-pass filter. The cutoff frequency is... , R It is the resistance corresponding to the state of a normal conductor. C It is the capacitance value.

2. A signal channel selection method suitable for superconducting quantum computing, characterized in that, Applied to DC signals, the method includes: For each input line, n output lines are constructed, with each output line constituting a signal channel. Each output line includes an illumination superconducting circuit, with one end connected to the input line and the other end grounded. This illumination superconducting circuit utilizes the temperature dependence of superconducting materials, using optical signals to radiate the superconducting material circuit and change its temperature, thereby achieving controllable switching between the superconducting state and the ordinary conductor state. An optical fiber is aligned with the illumination superconducting circuit, and then the optical fiber is connected to an external control laser. Controllable illumination is achieved by adjusting the control laser to provide or not provide optical signals. For each output line, when the superconducting light-irradiated line is heated by light radiation, the output line is in a resisted state; otherwise, it is in an unresisted superconducting state, and the output line at this time is the DC signal channel. In this way, the DC signal channel selection function is realized by selectively heating the n output lines with light radiation.

3. A signal channel selection method suitable for superconducting quantum computing according to claim 1 or 2, characterized in that, The illumination superconducting circuit adopts a two-dimensional nanoscale meandering circuit structure.

4. A signal channel selection device suitable for superconducting quantum computing, characterized in that, The device, applied to microwave signals, includes: one input line and n output lines; the one output line is a signal channel; the output line includes a capacitor and an illumination superconducting circuit, one end of the capacitor is connected to the input line, and the other end is connected to one end of the illumination superconducting circuit and a load, respectively; the other end of the illumination superconducting circuit is grounded; the illumination superconducting circuit utilizes the temperature dependence of superconducting materials, and changes the temperature of the superconducting material circuit by radiating the superconducting material circuit with an optical signal, thereby achieving controllable switching between the superconducting state and the ordinary conductor state of the superconducting material circuit; the illumination superconducting circuit is equipped with an optical fiber aligned with it, and the optical fiber is connected to an external control laser, and controllable illumination is achieved by adjusting the control laser to provide or not provide an optical signal; For each output line, when the illumination superconducting circuit is in a superconducting state, the output line is directly grounded, meaning the signal channel is closed, and the microwave signal input from the input line cannot be transmitted to the load through this signal channel. When the illumination superconducting circuit is in a normal conductor state, the output line forms an RC high-pass filter, meaning the signal channel is open, and the microwave signal input from the input line is transmitted to the load through the RC high-pass filter. The cutoff frequency is... , R It is the resistance corresponding to the state of a normal conductor. C It is the capacitance value.

5. A signal channel selection device suitable for superconducting quantum computing, characterized in that, For use with DC signals, the device includes: one input line and n output lines; the one output line is a signal channel; the output line includes an illumination superconducting circuit, one end of which is connected to the input line and the other end is grounded; the illumination superconducting circuit utilizes the temperature dependence of superconducting materials to change the temperature of the superconducting material circuit by radiating light signals, thereby achieving controllable switching between the superconducting state and the ordinary conductor state of the superconducting material circuit; the illumination superconducting circuit is equipped with an optical fiber aligned with it, and the optical fiber is connected to an external control laser, so that controllable illumination can be achieved by adjusting the control laser to provide or not provide light signals; For each output line, when the superconducting light-irradiated line is heated by light radiation, the output line is in a resisted state; otherwise, it is in an unresisted superconducting state, and the output line at this time is the DC signal channel. In this way, the DC signal channel selection function is realized by selectively heating the n output lines with light radiation.

6. A signal channel selection device suitable for superconducting quantum computing according to claim 4 or 5, characterized in that, The illumination superconducting circuit adopts a two-dimensional nanoscale meandering circuit structure.

7. A signal channel selection device suitable for superconducting quantum computing according to claim 4 or 5, characterized in that, The signal channel selection device is implemented by etching a thin film of superconducting material on the surface of an insulating substrate using micro-nano fabrication technology.

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