Measurement and control system of quantum computer and calibration method of related IQ frequency mixing component

Abstract

The invention discloses a measurement and control system of a quantum computer and a calibration method of a related IQ frequency mixing component. In the measurement and control system, an upper computer sends a first scanning instruction to a first waveform generation part; according to the frequency domain information obtained by the quantum analyzer, determining a first optimal parameter of the first waveform generation part and returning the first optimal parameter to the first waveform generation part, so that the first waveform generation part can emit a baseband signal corresponding to the first optimal parameter, and correcting the deviation of the first IQ frequency mixing part; the first waveform generation part sequentially transmits baseband signals corresponding to different independent variables according to the first scanning instruction; and the quantum analyzer controls the signal output by the signal monitoring unit to collect and analyze when the first waveform generation part executes the first scanning instruction, and outputs the analyzed frequency domain information to the upper computer. According to the invention, the IQ signal output by the first waveform generation component can be ensured to compensate the hardware deviation of the first IQ frequency mixing component, so as to achieve the optimal sideband suppression theoretically.

Description

Technical Field

[0001] The present invention relates to the field of quantum information technology, and in particular to a measurement and control system of a quantum computer and a calibration method for related IQ mixing components. Background Art

[0002] In the current superconducting quantum measurement and control system, users interact with the quantum measurement and control system through a host computer and a gigabit network switch. Specifically, the host computer transmits the desired arbitrary waveform to the arbitrary waveform generator (AWG) in the quantum measurement and control system. The quantum analyzer in the quantum measurement and control system collects signals from the quantum chip and sends the collected signals to the host computer for analysis and processing, thereby obtaining the current state of the quantum bit.

[0003] A typical example is to assume that the cavity frequency of the quantum bit has been found, and now its energy spectrum is sought. In theory, the AWG first transmits a control waveform, which is mixed with the microwave source by an IQ mixer and up-converted to a high-frequency signal of 4GHz-8GHz. This signal then enters the quantum chip, attempting to excite the quantum bit. The read signal transmission module then transmits a read signal to the quantum bit to read the state of the cavity and, in turn, the state of the quantum bit. Next, a quantum analyzer is used to read the signal, reading the state of the cavity and, in turn, the state of the bit. The read signal transmission module includes an AWG (which is different from the AWG in the control signal path) and an IQ mixer. The waveform emitted by the AWG is mixed with the pulse signal emitted by the microwave source by the IQ mixer to obtain the read signal.

[0004] The IQ mixers in the control signal path and the input signal path share the same structure, consisting of two mixers. The mixer output is the product of the two input signals. Using trigonometric functions and the difference product formula, theoretically, when the two signals are 90° out of phase, the IQ mixer can output a single-frequency signal, achieving sideband suppression. However, in practice, because the IQ mixers do not fully meet theoretical hardware specifications, they cannot achieve optimal sideband suppression. Summary of the Invention

[0005] In view of the above problems, the present invention is proposed to provide a measurement and control system of a quantum computer and a calibration method for related IQ mixing components that overcome the above problems or at least partially solve the above problems.

[0006] In a first aspect, an embodiment of the present invention provides a measurement and control system for a quantum computer, comprising: a control signal generating unit, a control signal monitoring unit, a quantum analyzer, and a host computer;

[0007] The control signal generating unit is used to generate a control signal for manipulating a quantum bit in a quantum processing unit of a quantum computer; the control signal generating unit includes: a first waveform generating component and a first IQ mixing component; the first waveform generating component is used to transmit a baseband signal of the control signal to the first IQ mixing component;

[0008] The input end of the control signal monitoring unit is connected to the control signal generating unit, and the output end is connected to the quantum analyzer and the quantum processing unit respectively; the control signal monitoring unit is used to couple out part of the control signal generated by the control signal generating unit, output it to the quantum analyzer after demodulation, and output the remaining control signal to the quantum processing unit to control the quantum bit;

[0009] The host computer is connected to the quantum analyzer and the first waveform generating component respectively;

[0010] The host computer is configured to send a first scanning instruction to the first waveform generating component; and determine a first optimal parameter for sideband suppression of the first waveform generating component based on frequency domain information obtained by the quantum analyzer; and return the first optimal parameter to the first waveform generating component, so that the first waveform generating component can transmit a baseband signal corresponding to the first optimal parameter, and correct the deviation of the first IQ mixing component;

[0011] The first waveform generating component is configured to sequentially transmit baseband signals corresponding to different independent variable sizes according to the first scanning instruction;

[0012] The quantum analyzer is used to collect and perform frequency domain analysis on the signal output by the control signal monitoring unit during the period when the first waveform generating component executes the first scanning instruction, and output the frequency domain information obtained by the analysis to the host computer.

[0013] In one embodiment, the host computer is specifically configured to generate a heat map based on the frequency domain information obtained by the quantum analyzer; and determine a first optimal parameter for sideband suppression of the first waveform generating component based on the heat map.

[0014] In one embodiment, the independent variable comprises: one or more of relative amplitude, phase and offset;

[0015] The host computer is further configured to use the spectrum amplitude of the quantum analyzer signal as a dependent variable corresponding to the independent variable, draw a heat map, identify points that meet the principles of the highest control signal amplitude, the lowest local oscillator leakage amplitude, and the lowest image frequency signal amplitude, and determine the first optimal parameter based on one or more of the relative amplitude, phase, and offset of the identified points.

[0016] In one embodiment, the quantum analyzer is specifically used to collect the signal output by the control signal monitoring unit during the execution of the scanning instruction by the first waveform generating component, perform Fourier transform to obtain the corresponding frequency domain signal, obtain the frequency domain information of the frequency domain signal, and output it to the host computer.

[0017] In one embodiment, the control signal monitoring unit includes: a first signal distribution device and a demodulation mixer; wherein:

[0018] The first signal distribution device is connected between the control signal generating unit and the quantum processing unit;

[0019] The input end of the demodulation mixer is connected to the first signal distribution device and the control signal generating unit respectively, and the output end of the demodulation mixer is connected to the quantum analyzer;

[0020] The first signal distribution device is configured to couple out a portion of the control signal generated by the control signal generating unit and output the coupled signal to the demodulation mixer, and output the remaining control signal to the quantum processing unit;

[0021] The demodulation mixer is used to demodulate the control signal coupled from the first signal distribution device and output the demodulated signal to the quantum analyzer;

[0022] The quantum analyzer is further used to collect and analyze the control signal demodulated by the demodulation mixer to monitor the control signal.

[0023] In one embodiment, the first waveform generating component is a first arbitrary waveform generator; the first IQ mixing component is a first IQ mixer;

[0024] The control signal generating unit further includes: a microwave source;

[0025] a first arbitrary waveform generator, configured to transmit a baseband signal to the first IQ mixer;

[0026] The input end of the first IQ mixer is connected to the first arbitrary waveform generator and the microwave source respectively; the output end of the first IQ mixer is connected to the first signal distribution device; the microwave source is used to output a local oscillator signal to the first IQ mixer;

[0027] The input end of the demodulation mixer is connected to the quantum processing unit, the output end of the first signal distribution device and the microwave source respectively, and the output end of the demodulation mixer is connected to the quantum analyzer;

[0028] The first IQ mixer is used to mix the baseband signal and the local oscillator signal and output the first signal to the first signal distribution device;

[0029] The microwave source is further configured to output a local oscillator signal for demodulating the control signal to the demodulation mixer;

[0030] The demodulation mixer is specifically used to mix the control signal output by the first signal distribution device with the local oscillator signal output by the microwave source, down-convert it into a signal that can be collected and analyzed by the quantum analyzer, and output it to the quantum analyzer.

[0031] In one embodiment, the control signal monitoring unit includes: a first signal distribution module, a first combiner, and a demodulation mixer;

[0032] The first combiner is provided between the first signal distribution module and the demodulation mixer;

[0033] The first signal distribution module includes a plurality of first signal distribution devices; the plurality of first signal distribution devices are connected to the first combiner;

[0034] The plurality of first signal distribution devices are respectively connected to the output terminals of the multiple channels of the control signal generating unit; each of the first signal distribution devices is used to couple out a portion of the control signal of the corresponding channel;

[0035] The first combiner is configured to combine and output signals obtained by coupling the plurality of first signal distribution devices;

[0036] The demodulation mixer is used to demodulate the signal output after the combination by the first combiner and input the demodulated signal into the quantum analyzer.

[0037] In one embodiment, the first waveform generating component is a first arbitrary waveform generating module; the first IQ mixing component is a first IQ mixing module;

[0038] The control signal generating unit further includes: a microwave source;

[0039] The input end of the demodulation mixer is connected to the quantum processing unit, the output end of the first combiner and the microwave source respectively, and the output end of the demodulation mixer is connected to the quantum analyzer;

[0040] The first arbitrary waveform generating module includes a plurality of first arbitrary waveform generators;

[0041] The first IQ mixing module includes a plurality of first IQ mixers;

[0042] The first arbitrary waveform generator in the first arbitrary waveform generating module is used to transmit a baseband signal to the first IQ mixer in the first IQ mixing module;

[0043] The microwave source is used to output a local oscillator signal to the first IQ mixer in the first IQ mixing module;

[0044] The first IQ mixer is used to mix the baseband signal and the local oscillator signal and output the first signal to the first signal distribution device;

[0045] The multiple first IQ mixers in the first IQ mixing module are respectively connected to the multiple first arbitrary waveform generators in the first arbitrary waveform generating module and the output ends of the microwave source multi-channel to form multiple control signal generation channels; wherein the input end of each of the first IQ mixers is respectively connected to the microwave source and the first arbitrary waveform generator of the same channel; and the output end of each of the first IQ mixers is respectively connected to the input end of the first signal distribution device of the same channel of the first signal distribution module;

[0046] The input end of the demodulation mixer is connected to the quantum processing unit, the output end of the first combiner and the microwave source respectively, and the output end of the demodulation mixer is connected to the quantum analyzer;

[0047] The microwave source is used to output a local oscillator signal for demodulating the control signal to the demodulation mixer;

[0048] The demodulation mixer is specifically used to mix the signal output after the combination of the first combiner with the local oscillator signal for demodulating the control signal, and down-convert it into a signal that can be collected and analyzed by the quantum analyzer.

[0049] In one embodiment, the measurement and control system further comprises: a read-in signal generating unit and a read-in signal monitoring unit;

[0050] The read-in signal generating unit is used to generate a read-in signal to a quantum processing unit of a quantum computer to read the state of a quantum bit in the quantum processing unit; the read-in signal generating unit includes: a second waveform generating component and a second IQ mixing component; the second waveform generating component is used to transmit a baseband signal of the read-in signal to the second IQ mixing component;

[0051] The read-in signal monitoring unit is used to couple out a portion of the read-in signal generated by the read-in signal generating unit, output it to the quantum analyzer after demodulation, and output the remaining read-in signal to the quantum processing unit;

[0052] The host computer is also connected to the second waveform generating component;

[0053] The host computer is further configured to send a second scanning instruction to the second waveform generating component; and determine a second optimal parameter for sideband suppression of the second waveform generating component based on the frequency domain information obtained by the quantum analyzer; and return the second optimal parameter to the second waveform generating component, so that the second waveform generating component can transmit a baseband signal corresponding to the second optimal parameter, and correct the deviation of the second IQ mixing component;

[0054] The second waveform generating component is configured to sequentially transmit baseband signals corresponding to different independent variable sizes according to the second scanning instruction;

[0055] The quantum analyzer is used to collect and perform frequency domain analysis on the signal output by the input signal monitoring unit during the execution of the second scanning instruction by the second waveform generating component, and output the frequency domain information obtained by the analysis to the host computer.

[0056] In one embodiment, the host computer is specifically configured to generate a heat map based on the frequency domain information obtained by the quantum analyzer; and determine the second optimal parameter for sideband suppression of the second waveform generating component based on the heat map.

[0057] In one embodiment, the independent variable comprises: one or more of relative amplitude, phase and offset;

[0058] The host computer is further configured to use the spectrum amplitude of the signal collected by the quantum analyzer as a dependent variable corresponding to the independent variable, draw a heat map, identify points that meet the principles of the highest amplitude of the read signal, the lowest amplitude of the local oscillator leakage, and the lowest amplitude of the image frequency signal, and determine the second optimal parameter based on one or more of the relative amplitude, phase, and offset of the identified points.

[0059] In one embodiment, the quantum analyzer is specifically used to collect the signal output by the read-in signal monitoring unit during the execution of the scanning instruction by the second waveform generating component, perform Fourier transform on the signal to obtain the corresponding frequency domain signal, obtain the frequency domain information of the frequency domain signal, and output it to the host computer.

[0060] In one embodiment, the read-in signal monitoring unit includes: a second signal distribution device and a demodulation mixing module;

[0061] The second signal distribution device is connected between the read-in signal generating unit and the quantum processing unit, and is used to couple out a portion of the read-in signal generated by the read-in signal generating unit and output it to the demodulation mixing module, and output the remaining read-in signal to the quantum processing unit;

[0062] The input end of the demodulation mixing module is connected to the second signal distribution device and the read-in signal generating unit respectively, and the output end of the demodulation mixing module is connected to the quantum analyzer;

[0063] The demodulation mixing module is used to demodulate the read signal coupled from the second signal distribution device and output it to the quantum analyzer;

[0064] The quantum analyzer is further configured to collect and analyze the read-in signal demodulated by the demodulation mixing module, so as to monitor the read-in signal and / or monitor the relative sequence of the control signal and the read-in signal.

[0065] In one embodiment, the second waveform generating component is a second arbitrary waveform generator; the second IQ mixing component is a second IQ mixer;

[0066] The read-in signal generating unit further includes: a microwave source;

[0067] a second arbitrary waveform generator, configured to transmit a baseband signal to the second IQ mixer;

[0068] The input end of the second IQ mixer is connected to the second arbitrary waveform generator and the microwave source respectively; the output end of the second IQ mixer is connected to the second signal distribution device; the microwave source is used to output a local oscillator signal to the second IQ mixer;

[0069] The input end of the demodulation mixing module is connected to the quantum processing unit, the output end of the second signal distribution device and the microwave source respectively, and the output end of the demodulation mixer is connected to the quantum analyzer;

[0070] The second IQ mixer is used to mix the baseband signal and the local oscillator signal and output the second signal to the second signal distribution device;

[0071] The microwave source is further configured to output a local oscillator signal for demodulating the control signal to the demodulation mixing module;

[0072] The demodulation mixing module is specifically used to mix the read signal output by the second signal distribution device with the local oscillator signal output by the microwave source, down-convert it into a signal that can be collected and analyzed by the quantum analyzer, and output it to the quantum analyzer.

[0073] In one embodiment, the read-in signal monitoring unit includes: a second signal distribution module and a second combiner and demodulation mixing module;

[0074] The second combiner is provided between the second signal distribution module and the demodulation mixing module;

[0075] The second signal distribution module includes a plurality of second signal distribution devices; the plurality of second signal distribution devices are connected to the second combiner;

[0076] The plurality of second signal distribution devices are respectively connected to the output ends of the multiple channels of the read-in signal generating unit; each second signal distribution device is used to couple out part of the read-in signal of the corresponding channel;

[0077] The second combiner is used to combine and output the signals obtained by coupling the plurality of second signal distribution devices;

[0078] The demodulation mixing module is used to demodulate the signal output after the second combiner combines and then input it into the quantum analyzer.

[0079] In one embodiment, the second waveform generating component is a second arbitrary waveform generating module; the second IQ mixing component is a second IQ mixing module;

[0080] The read-in signal generating unit further includes: a microwave source;

[0081] The input end of the demodulation mixing module is connected to the quantum processing unit, the output end of the second combiner and the microwave source respectively, and the output end of the demodulation mixing module is connected to the quantum analyzer;

[0082] The second arbitrary waveform generating module includes a plurality of second arbitrary waveform generators;

[0083] The second IQ mixing module includes a plurality of second IQ mixers;

[0084] The second arbitrary waveform generator in the second arbitrary waveform generating module is used to transmit a baseband signal to the second IQ mixer in the second IQ mixing module;

[0085] The microwave source is used to output a local oscillator signal to the second IQ mixer in the second IQ mixing module;

[0086] The second IQ mixer is used to mix the baseband signal and the local oscillator signal and output the second signal to the second signal distribution device;

[0087] The plurality of second IQ mixers in the second IQ mixing module are respectively connected to the plurality of second arbitrary waveform generators in the second arbitrary waveform generating module and the output ends of the microwave source multi-channel to form a plurality of read-in signal generation channels; wherein the input end of each second IQ mixer is respectively connected to the microwave source and the second arbitrary waveform generator of the same channel; and the output end of each second IQ mixer is respectively connected to the input end of the second signal distribution device of the same channel of the second signal distribution module;

[0088] The microwave source is used to output a local oscillator signal for demodulating the read signal to the demodulation mixer;

[0089] The demodulation mixing module is specifically used to mix the signal output after the second combiner is combined with the local oscillator signal for demodulating the read signal, and down-convert it into a signal that can be collected and analyzed by the quantum analyzer;

[0090] The quantum analyzer is further configured to collect and analyze the read-in signal demodulated by the demodulation mixing module, so as to monitor the read-in signal and / or monitor the relative sequence of the control signal and the read-in signal.

[0091] In one embodiment, the second waveform generating component is a second arbitrary waveform generating module; the second IQ mixing component is a second IQ mixing module;

[0092] The read-in signal generating unit further includes: a microwave source;

[0093] The input end of the demodulation mixing module is connected to the quantum processing unit, the output end of the second combiner and the microwave source respectively, and the output end of the demodulation mixing module is connected to the quantum analyzer;

[0094] The second arbitrary waveform generating module includes a second arbitrary waveform generator having a multi-channel output terminal;

[0095] The second IQ mixing module includes a plurality of second IQ mixers;

[0096] The second arbitrary waveform generator in the second arbitrary waveform generating module is used to transmit a baseband signal to the second IQ mixer in the second IQ mixing module;

[0097] The microwave source is used to output a local oscillator signal to the second IQ mixer in the second IQ mixing module;

[0098] The second IQ mixer is used to mix the baseband signal and the local oscillator signal and output the second signal to the second signal distribution device;

[0099] The plurality of second IQ mixers in the second IQ mixing module are respectively connected to the output ends of the multi-channels of the second arbitrary waveform generation module and the output ends of the multi-channels of the microwave source to form a plurality of read-in signal generation channels; wherein the input end of each second IQ mixer is respectively connected to the output ends of the microwave source and the second arbitrary waveform generator of the same channel; and the output end of each second IQ mixer is respectively connected to the input end of the second signal distribution device of the same channel of the second signal distribution module;

[0100] The microwave source is used to output a local oscillator signal for demodulating the read signal to the demodulation mixer;

[0101] The demodulation mixing module is specifically used to mix the signal output after the second combiner is combined with the local oscillator signal for demodulating the read signal, and down-convert it into a signal that can be collected and analyzed by the quantum analyzer;

[0102] The quantum analyzer is further configured to collect and analyze the read-in signal demodulated by the demodulation mixing module, so as to monitor the read-in signal and / or monitor the relative sequence of the control signal and the read-in signal.

[0103] In one embodiment, the read-in signal generating unit and the control signal generating unit share the same microwave source.

[0104] In one embodiment, the microwave source comprises at least two channels with different carrier frequencies;

[0105] During the deviation correction of the first IQ mixing component, the first IQ mixing component and the demodulation mixer respectively use local oscillator signals output by channels of different carrier frequencies of the microwave source;

[0106] During the process of correcting the deviation of the second IQ mixing component, the second IQ mixing component and the demodulation mixing module respectively use local oscillator signals output by channels of different carrier frequencies of the microwave source.

[0107] In one embodiment, the first signal distribution device is a power splitter or a directional coupler;

[0108] The second signal distribution device is a power splitter or a directional coupler.

[0109] In one embodiment, the measurement and control system is a measurement and control system in a superconducting quantum computer, and the quantum processing unit is a superconducting quantum chip.

[0110] In a second aspect, an embodiment of the present invention provides a quantum computer, comprising: a measurement and control system and a quantum processing unit as described above for the quantum computer;

[0111] The control signal monitoring unit in the measurement and control system is connected to the quantum processing unit, and is used to couple out a portion of the control signal emitted by the control signal generating unit in the measurement and control system, demodulate and output it to the quantum analyzer for collection and analysis, and output the remaining control signal to the quantum processing unit for controlling the quantum bit.

[0112] In a third aspect, an embodiment of the present invention provides a method for calibrating an IQ mixing component in a measurement and control system of the aforementioned quantum computer, comprising:

[0113] The host computer sends a first scanning instruction to the first waveform generating component in the control signal generating unit;

[0114] The first waveform generating component sequentially transmits IQ signals corresponding to different independent variable sizes according to the first scanning instruction;

[0115] The quantum analyzer collects the signal output by the control signal monitoring unit during the execution of the first scanning instruction by the first waveform generating component and performs frequency domain analysis, and outputs the frequency domain information obtained by the analysis to the host computer;

[0116] The host computer determines the first optimal parameter for sideband suppression of the first waveform generating component based on the frequency domain information obtained by the quantum analyzer; and returns the first optimal parameter to the first waveform generating component, so that the first waveform generating component can transmit a baseband signal corresponding to the first optimal parameter and correct the deviation of the first IQ mixing component.

[0117] In one embodiment, the method for calibrating the IQ mixing component in the measurement and control system of the quantum computer further includes:

[0118] The host computer sends a second scanning instruction to the second waveform generating component in the read-in signal generating unit;

[0119] The second waveform generating component sequentially transmits IQ signals corresponding to different independent variables according to the second scanning instruction;

[0120] The quantum analyzer collects the signal output by the control signal monitoring unit during the execution of the second scanning instruction by the first waveform generating component and performs frequency domain analysis, and outputs the frequency domain information obtained by the analysis to the host computer;

[0121] The host computer determines the second optimal parameters for sideband suppression of the second waveform generating component based on the frequency domain information obtained by the quantum analyzer; and returns the second optimal parameters to the second waveform generating component, so that the second waveform generating component can transmit a baseband signal corresponding to the second optimal parameters and correct the deviation of the second IQ mixing component.

[0122] The beneficial effects of the above technical solutions provided by the embodiments of the present invention include at least:

[0123] Embodiments of the present invention provide a measurement and control system for a quantum computer and a calibration method for related IQ mixing components. On the one hand, a control signal monitoring unit is connected between a control signal generating unit and a quantum analyzer. The control signal monitoring unit couples out a portion of the control signal, demodulates it, and outputs it to the quantum analyzer for signal acquisition and analysis. This enables real-time monitoring of the control signal and improves the efficiency of control signal monitoring. On the other hand, based on the overall architecture in which the control signal monitoring unit can obtain the demodulated control signal in real time, a host computer sends a scanning instruction to a first waveform generating component, causing the first waveform generating component to sequentially transmit IQ signals (baseband signals used to generate control signals) corresponding to different independent variable sizes. Ultimately, the quantum analyzer and the host computer determine the first optimal parameters for the IQ signal transmitted by the first waveform generating component, ensuring that the IQ signal output by the first waveform generating component meets the hardware requirements for sideband suppression, thereby compensating for hardware deviations in the first IQ mixing component, achieving theoretically optimal sideband suppression, and calibrating the first IQ mixing component.

[0124] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0125] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0126] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0127] Figure 1 This is an architectural diagram of a measurement and control system for a quantum computer in the prior art;

[0128] Figure 2 Schematic diagram of the architecture of the measurement and control system of the quantum computer in Example 1 of the present invention;

[0129] Figure 3 Schematic diagram of the architecture of the measurement and control system of a quantum computer in the case of a single control signal channel in Example 1 of the present invention;

[0130] Figure 4 This is a schematic diagram of the architecture of a measurement and control system for a quantum computer in the case of multi-channel control signals in Example 2 of the present invention;

[0131] Figure 5 Schematic diagram of the architecture of a measurement and control system for a quantum computer in the case where the control signal and the read-in signal are single-channel in Example 3 of the present invention;

[0132] Figure 6 Schematic diagram of the architecture of a measurement and control system for a quantum computer in a fourth embodiment of the present invention when control signals and read-in signals are multi-channel;

[0133] Figure 7 An overall block diagram of the structure of a quantum computer provided by an embodiment of the present invention;

[0134] Figure 8 This is a flow chart of a method for calibrating an IQ mixing component provided by an embodiment of the present invention.

[0135] Description of reference numerals:

[0136] 1. Control signal generating unit; 2. Control signal monitoring unit; 3. Quantum analyzer; 4. First signal distribution device; 5. Demodulation mixer; 6. First arbitrary waveform generator; 7. First IQ mixer; 8. Microwave source; 9. First signal distribution module; 10. First combiner; 11. First arbitrary waveform generating module; 12. First IQ mixer; 13. Second arbitrary waveform generator; 14. Second IQ mixer; 15. Second signal distribution device; 16. Demodulation mixer; 17. Second arbitrary waveform generating module; 18. Second IQ mixer; 19. Second combiner; 20. Host computer; 21. Switch; 22. Quantum processing unit; 23. Second signal distribution module; 24. Measurement and control system of quantum computer; 25. Read-in signal generating unit; 26. Read-in signal monitoring unit; 27. First waveform generating component; 28. First IQ mixer; 29. ​​Second waveform generating component; 30. Second IQ mixer. DETAILED DESCRIPTION

[0137] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0138] The architecture of the existing quantum computer measurement and control system, refer to Figure 1As shown, in the control signal generation path, the control signal is generated by the AWG, mixed and modulated by the IQ mixer with the high-frequency signal emitted by the microwave source, and then up-converted to a frequency range of, for example, 4 GHz to 8 GHz before entering the quantum processing unit. If the arbitrary waveform generator (AWG) is suspected of not outputting the control signal, or the output control signal does not meet expectations, the solution is to change the AWG's connection cable and connect its output directly to an external oscilloscope. The oscilloscope can then be used to check whether the actual output waveform matches the theoretical waveform generated by the software. Because high-bandwidth oscilloscopes (above 4 GHz) are very expensive, they generally only check the signal emitted by the AWG before mixing (typically with a frequency range of several hundred MHz). This inspection method is inefficient, and changing the wiring back and forth also brings other risks. For example, when restoring the measurement and control circuit, incorrect connections may be made, and repeated twisting of the RF connector may loosen or deform it. Furthermore, with existing technology architectures, if the IQ mixer does not meet theoretical hardware specifications, optimal sideband suppression cannot be achieved, and the IQ mixer cannot be calibrated.

[0139] To address the above-mentioned problems in the prior art, embodiments of the present invention provide an improved architecture for a measurement and control system for a quantum computer, thereby enabling automatic, real-time signal monitoring and improving signal monitoring efficiency. Furthermore, based on this architecture, the IQ mixer can also be adjusted simultaneously to ensure that the IQ mixer achieves optimal sideband suppression.

[0140] Example 1:

[0141] Based on the problems existing in the prior art, the embodiment of the present invention provides a measurement and control system for a quantum computer, referring to Figure 2 As shown, it includes: a control signal generating unit 1, a control signal monitoring unit 2, a quantum analyzer 3, and a host computer 20; wherein:

[0142] The control signal generating unit 1 is used to generate a control signal for manipulating the quantum bits in the quantum processing unit 22 of the quantum computer. The control signal generating unit 1 includes: a first waveform generating component 27 and a first IQ mixing component 28. The first waveform generating component 27 is used to transmit a baseband signal of the control signal to the first IQ mixing component 28.

[0143] The input end of the control signal monitoring unit 2 is connected to the control signal generating unit 1, and the output end is connected to the quantum analyzer 3 and the quantum processing unit 22 respectively; the control signal monitoring unit 2 is used to couple out the control signal generated by the control signal generating unit, output it to the quantum analyzer 3 after demodulation, and output the remaining control signal to the quantum processing unit 22 to control the quantum bit;

[0144] The host computer 20 is connected to the quantum analyzer 3 and the first waveform generating component 27 respectively;

[0145] The host computer is configured to send a first scanning instruction to the first waveform generating component 27; determine a first optimal parameter for sideband suppression of the first waveform generating component 27 based on the frequency domain information obtained by the quantum analyzer 3; and return the first optimal parameter to the first waveform generating component 27, so that the first waveform generating component 27 can transmit a baseband signal (IQ signal) corresponding to the first optimal parameter to correct the deviation of the first IQ mixing component 28;

[0146] A first waveform generating component 27 is configured to sequentially transmit baseband signals corresponding to different independent variable sizes according to the first scanning instruction;

[0147] The quantum analyzer 3 is used to collect and perform frequency domain analysis on the signal output by the control signal monitoring unit 2 during the execution of the first scanning instruction by the first waveform generating component 27 , and output the frequency domain information obtained by the analysis to the host computer 20 .

[0148] It should be noted that in the embodiments of the present invention, for the convenience of explanation, the relevant components, instructions, parameters, etc. of the control path and the read path in the measurement and control system of the quantum computer are distinguished and respectively referred to by the prefixes of "first" and "second", but "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0149] The measurement and control system of the quantum computer, on the one hand, is connected between the control signal generating unit and the quantum analyzer via a control signal monitoring unit. The control signal monitoring unit couples out a portion of the control signal, demodulates it, and outputs it to the quantum analyzer for signal acquisition and analysis. This enables real-time monitoring of the control signal and improves the efficiency of control signal monitoring. On the other hand, based on the overall architecture of the control signal monitoring unit capable of acquiring the demodulated control signal in real time, a host computer sends a scanning instruction to the first waveform generating component, causing the first waveform generating component to sequentially transmit IQ signals (baseband signals used to generate control signals) corresponding to different independent variable sizes. Ultimately, the quantum analyzer and the host computer determine the first optimal parameters for transmitting the IQ signal from the first waveform generating component, so that the IQ signal output by the first waveform generating component meets the hardware requirements for sideband suppression, thereby compensating for hardware deviations in the first IQ mixing component, achieving theoretically optimal sideband suppression, and calibrating the first IQ mixing component.

[0150] In some embodiments, the host computer has complex analysis and logic judgment functions by installing software, and can analyze frequency domain information to obtain the first optimal parameters for sideband suppression of the first waveform generating component 27.

[0151] In one embodiment, the first IQ mixing component 28 is calibrated, for example, by adjusting the offset and / or phase of the IQ signal output by the first waveform generating component 27 to compensate for the hardware deviation of the first IQ mixing component 28 to achieve theoretically optimal sideband suppression.

[0152] The host computer 20 can control the first waveform generating component 27 by sending a first scanning instruction, and change the size of the independent variable (such as one or more of the relative amplitude, phase, and offset), that is, sequentially transmit IQ signals corresponding to different independent variable sizes. During the scanning process, the size of the independent variable can be changed step by step with a specific step size. For example, such as scanning the phase, the initial phase of the I signal is set to 0°, and the initial phase of the Q signal is changed by 1° each step from 80° to 100°, and a total of 21 experiments are performed.

[0153] Correspondingly, the quantum analyzer 3 collects the signal output by the control signal monitoring unit 2 during the execution of the first scanning instruction by the first waveform generating component 27, performs Fourier transform on the collected signal to obtain a corresponding frequency domain signal, obtains frequency domain information of the frequency domain signal, and outputs it to the host computer 20.

[0154] Accordingly, the host computer 20 is used to generate a heat map based on the frequency domain information obtained by the quantum analyzer 3; and determine the first optimal parameter of the sideband suppression of the first waveform generating component 27 based on the heat map.

[0155] The host computer 20 uses the spectrum amplitude of the signal collected by the quantum analyzer 3 as the dependent variable corresponding to the independent variable (one or more of the relative amplitude, phase and offset), draws a heat map, identifies the points that meet the principles of the highest amplitude of the control signal, the lowest amplitude of the local oscillator leakage, and the lowest amplitude of the image frequency signal, and determines the first optimal parameter based on the relative amplitude, phase and offset of the identified points.

[0156] For identifying points that meet the principles of the highest control signal amplitude, the lowest local oscillator leakage amplitude, and the lowest image frequency signal amplitude, one approach is for the host computer to identify them using preset identification rules. Another approach is for the host computer to interact with a person with relevant technical knowledge to complete the identification process, that is, with the assistance of the host computer 20, the identification is completed through an interactive approach. The embodiments of the present invention are not limited to which method is used.

[0157] Taking the aforementioned example of scanning phase, the host computer 20 generates a heat map based on the received frequency domain information, and identifies the size of the parameter (phase in this example) corresponding to the experiment with the lowest mirror image from the results in the heat map. Assuming it is 0° and 88°, the first optimal parameter is: the phase of the I signal is 0°, and the phase of the Q signal is 88°.

[0158] This result shows that, theoretically, the IQ signals output by the first waveform generating component 27 should have a phase difference of 90°, allowing the first IQ mixing component 28 to output a single-frequency signal to achieve sideband suppression. However, experiments have shown that due to hardware deviations in the first IQ mixing component 28, a 90° phase difference in the IQ signals does not achieve sideband suppression. After the calibration process, when the phases of the IQ signals output by the first waveform generating component 27 are 0° and 88°, respectively, the output of the first IQ mixing component 28 meets the requirements of achieving the highest control signal amplitude, the lowest local oscillator leakage amplitude, and the lowest image frequency signal amplitude, thus achieving optimal sideband suppression.

[0159] The host computer returns the above-mentioned first optimal parameters to the first waveform generating component 27, so that the first waveform generating component 27 adjusts the offset and / or phase of the transmitted baseband signal, so that the adjusted first waveform generating component 27 can transmit a baseband signal (IQ signal) that meets the first optimal parameters. After the baseband signal enters the first IQ mixing component 28, the first IQ mixing component 28 can perform mixing according to the actual first optimal parameters and correct the deviation of the first IQ mixing component 28 to ensure that the amplitude of the control signal is maximized, the amplitude of the local oscillator leakage is minimized, and the amplitude of the image frequency signal is minimized.

[0160] In some embodiments, the quantum analyzer can collect and perform simple analysis on the demodulated signal, and then output it to the upper-level host computer connected to the quantum analyzer for further analysis and logical judgment, such as whether the control signal is correctly sent, whether the order of the control signal and the read signal is correct, etc.

[0161] In other embodiments, the quantum analyzer has complex analysis and judgment functions. After collecting and analyzing the demodulated signal, it can directly further analyze and judge whether the control signal is correctly sent, whether the sequence of the control signal and the input signal is correct, etc. In other words, it integrates the corresponding functions of the above-mentioned host computer.

[0162] When the quantum computer is, for example, a superconducting quantum computer, the control signal is a microwave signal used to control the qubit, for example, to control the qubit's arbitrary rotation around the X or Y axis of the Bloch sphere. When the frequency of the control signal is equal to the frequency of the qubit, the qubit is excited. The frequency range of the control signal is, for example, 4 GHz to 8 GHz. It is understood that when the quantum computer is a suitable type of quantum computer other than a superconducting quantum computer, the control signal may also correspond to a signal of other frequencies, and this application is not limited to this.

[0163] In the measurement and control system 24 of the quantum computer provided in an embodiment of the present invention, a control signal monitoring unit 2 is connected between the control signal generating unit 1 and the quantum analyzer 3. The control signal monitoring unit 2 couples out a portion of the control signal, demodulates it, and outputs it to the quantum analyzer 3. The quantum analyzer 3 then collects and analyzes the signal. This allows real-time monitoring of the control signal, improving monitoring efficiency. Furthermore, since the connection relationship of the quantum computer's measurement and control system does not need to be changed during the monitoring process, the risk of incorrect connection of the post-inspection restoration circuit is avoided. Furthermore, based on the aforementioned architecture for real-time monitoring of the control signal, it is also convenient to use the first waveform generating component to execute a scanning instruction, find the first optimal parameters through the host computer, and return them to the first waveform generating component. The baseband signal used to generate the control signal is transmitted according to the first optimal parameters, thereby calibrating the first IQ mixing component.

[0164] In one embodiment, referring to Figure 3 As shown, the control signal monitoring unit 2 in the measurement and control system of the quantum computer includes, for example but not limited to, a first signal distribution device 4 and a demodulation mixer 5; wherein:

[0165] The first signal distribution device 4 is connected between the control signal generating unit 1 and the quantum processing unit 22;

[0166] The input end of the demodulation mixer 5 is connected to the first signal distribution device 4 and the control signal generating unit 1 respectively, and the output end of the demodulation mixer 5 is connected to the quantum analyzer 3;

[0167] a first signal distribution device 4 for coupling out a portion of the control signal generated by the control signal generating unit 1 to output to the quantum analyzer 3 for analysis and monitoring of the control signal, and outputting the remaining control signal to the quantum bits of the quantum processing unit 22 for control operation;

[0168] A demodulation mixer 5 is used to demodulate the control signal coupled from the first signal distribution device 4 and output the demodulated signal to the quantum analyzer 3;

[0169] The quantum analyzer 3 is used, on the one hand, to collect and analyze the control signal demodulated by the demodulation mixer 5 to achieve real-time monitoring of the control signal. On the other hand, during the calibration process of the first IQ mixing component, the quantum analyzer 3 collects and performs frequency analysis on the signal output by the demodulation mixer 5, and outputs the frequency domain information obtained from the analysis to the host computer 20, so that the host computer 20 can determine the first optimal parameters of the first waveform generating component.

[0170] The first signal distribution device 4 may be implemented as a power splitter or a directional coupler, etc. However, the first signal distribution device 4 may also be other suitable types of electronic devices.

[0171] The main function of a power splitter is to split an input signal into multiple output signals. A power splitter generally consists of an input port, an output port, a reflector port, a resonant cavity, and electromagnetic components. The operating principle and structure of a power splitter can be found in the prior art.

[0172] A directional coupler is a passive, reciprocal four-port device, one of which is isolated from the input port. Ideally, all four ports are perfectly matched, and the circuit is lossless. Directional couplers can be implemented in a variety of ways, including microstrip, stripline, coaxial, and waveguide.

[0173] Directional couplers are typically implemented by exploiting the distributed nature of microwave circuits. Signal coupling typically occurs at a quarter wavelength or an integer multiple thereof. In these distributed couplers, the energy and field interactions between two adjacent circuit components couple the signal from one circuit structure to the other. The specific structure and implementation principles can be found in existing technologies.

[0174] Continue to refer to Figure 3 As shown, specifically, the first waveform generating component 27 may be, for example, a first arbitrary waveform generator 6; the first IQ mixing component 28 may be, for example, a first IQ mixer 7;

[0175] Reference Figure 2 and Figure 3 As shown, the control signal generating unit 1 may further include, in addition to the above-mentioned first arbitrary waveform generator 6 and first IQ mixer 7, a microwave source 8;

[0176] The first arbitrary waveform generator 6 is configured to transmit a baseband signal to the first IQ mixer;

[0177] The microwave source 8 is used to output a local oscillator signal to the first IQ mixer;

[0178] The input end of the first IQ mixer 7 is connected to the first arbitrary waveform generator 6 and the microwave source 8 respectively; the output end of the first IQ mixer 7 is connected to the first signal distribution device 4;

[0179] The microwave source 8 is used to provide microwave signals to the first IQ mixer 7 and the demodulation mixer 5;

[0180] The input end of the demodulation mixer 5 is respectively connected to the quantum processing unit 22, the output end of the first signal distribution device 4 and the microwave source 8, and the output end of the demodulation mixer 5 is connected to the quantum analyzer 3;

[0181] The first IQ mixer 7 is used to mix the baseband signal and the local oscillator signal and output the first signal to the first signal distribution device 4;

[0182] The microwave source 8 is further configured to output a local oscillator signal for demodulating the control signal to the demodulation mixer 5;

[0183] The demodulation mixer 5 is specifically used to mix the control signal output by the first signal distribution device 4 with the local oscillator signal output by the microwave source 8, down-convert it into a signal that can be collected and analyzed by the quantum analyzer 3, and output it to the quantum analyzer 3.

[0184] In the first embodiment, during the real-time monitoring of the control signal, the microwave signal output by the microwave source 8 to the first IQ mixer 7 is the same as the microwave signal output to the demodulation mixer 5 .

[0185] In the demodulation mixer 5, the output signal is equal to the product of the input signals, and the product in the time domain corresponds to the convolution in the frequency domain. In the embodiment of the present invention, the high frequency carrier can be down-converted into an intermediate frequency signal.

[0186] An arbitrary waveform generator (AWG) is a signal source that can generate any desired waveform. It can generate the desired waveform using digital data (such as control parameters) sent by the connected host computer.

[0187] An IQ mixer consists of two mixers with an internal bridge circuit to achieve sideband suppression. The intermediate frequency (IF) consists of two I and Q channels, while the LO (Lower Frequency) channel has an internal bridge circuit and consists of two mixers. When used for upconversion, an IQ mixer is also called a sideband suppression mixer, with a bridge circuit added to the IF port. Selecting the input bridge port selects the upper or lower RF sideband. Adjusting the IQ bias voltage adjusts LO local oscillator leakage. Sideband suppression is also controlled by the balance of the IQ channels. The specific structure of the IQ mixer can be found in existing technology.

[0188] It should be noted that, as mentioned above, during the calibration of the first IQ mixing component 28 (for example, the first IQ mixer 7), the first arbitrary waveform generator 6 can transmit IQ signals corresponding to different independent variables in sequence with a preset step size according to the first scanning instruction given by the host computer 20, and receive the first optimal parameters returned by the host computer 20, thereby generating an IQ signal corresponding to the first optimal parameters under the control of the host computer.

[0189] During the calibration of the first IQ mixer, unlike the real-time monitoring process, demodulation uses and modulates carriers of different frequencies. For example, the first arbitrary waveform generator 6 transmits a 100 MHz IQ signal. In the first IQ mixer 7, this 100 MHz IQ signal is mixed with a 5 GHz Lo (local oscillator) signal to generate three signals: 5.1 GHz (control signal), 5 GHz (local oscillator leakage), and 4.9 GHz (image signal, requiring suppression). After passing through the first signal distribution device 4 (e.g., a directional coupler), the signal is demodulated with the 4.99 GHz local oscillator Lo signal, generating three signals: 110 MHz (corresponding to the control signal), 10 MHz (corresponding to local oscillator leakage), and 90 MHz (corresponding to the image signal). The quantum analyzer collects these signals and performs a Fourier transform to obtain the corresponding frequency domain information. The relative amplitude, phase, and offset of the IQ signal are used as independent variables and scanned. The independent variables are varied with a set step size during the scan. The spectrum amplitude of the collected signal is used as the dependent variable to plot a heat map, thereby obtaining the first optimal parameters for IQ signal sideband suppression.

[0190] The above-mentioned technical means of demodulating and modulating carrier waves of different frequencies can be specifically implemented in the following manner: the microwave source includes at least two channels with different carrier frequencies;

[0191] During the process of correcting the deviation of the first IQ mixer 7 , the first IQ mixer 7 and the demodulation mixer 5 respectively use the local oscillator signals (Lo) outputted by channels of different carrier frequencies of the microwave source 8 .

[0192] Taking the phase parameters of 0° and 88° as an example, the host computer returns these phase parameters to the first arbitrary waveform generator 6. Thereafter, the IQ output signals of the first arbitrary waveform generator 6 are calibrated to phases of 0° and 88°, respectively. This calibration process for the first IQ mixer can be automated through the host computer software without requiring changes to the hardware architecture, making it easy to implement and highly efficient.

[0193] Regarding the process of real-time signal monitoring by the above-mentioned architecture, in the measurement and control system of the above-mentioned quantum computer provided by the embodiment of the present invention, a first signal distribution device 4 is provided between the first IQ mixer 7 and the quantum processing unit 22. After the baseband signal emitted by the first arbitrary waveform generator 6 is mixed with the local oscillator signal output by the microwave source 8, before entering the quantum processing unit 22, the first signal distribution device 4 can couple out a part of the control signal, and a part of the control signal enters the quantum processing unit 22. The coupled control signal is connected to the demodulation mixer 5, mixed with the microwave signal output by the microwave source 8, and down-converted into the quantum analyzer 3. The signals that can be collected, such as intermediate frequency signals (with a frequency of several hundred MHz), are up-converted by the microwave source 8 using a microwave signal of the same frequency to the baseband signal output by the first arbitrary waveform generator 6 and down-convert the control signal output by the first IQ mixer 7. Therefore, the signals collected by the quantum analyzer 3 and the signals emitted by the first arbitrary waveform generator 6 have the same frequency and timing, and some amplitude variations, but they are completely linearly aligned. This ensures the consistency of the monitored signal with the control signal originally emitted by the first arbitrary waveform generator 6, enabling real-time monitoring of the original transmitted signal of the first arbitrary waveform generator 6.

[0194] At the same time, due to the above Figure 3 The illustrated architecture includes a portion for modulating the control signal (the first IQ mixer 7 and the microwave source 8). The first signal distribution device 4, the demodulation mixer 5, and the quantum analyzer 3 can also be used to detect problems with the high-frequency circuit (the first IQ mixer 7 and the microwave source 8). For example, the performance of the first IQ mixer 7 is normal, the microwave source 8 is transmitting normally, and the frequency used is correct.

[0195] The process of real-time monitoring of the control signal by the quantum measurement and control system is briefly described as follows:

[0196] The first arbitrary waveform generator 6 transmits the required baseband signal. The baseband signal generally includes two parts: an I signal and a Q signal. The baseband signal is input to the first IQ mixer 7. In the first IQ mixer 7, the baseband signal is mixed with the local oscillator signal output by the microwave source 8 to generate a high-frequency signal. After a portion of the signal is coupled out by the first signal distribution device 4, the coupled signal is connected to the demodulation mixer 5, and then mixed with the microwave signal output by the microwave source 8. The signal is down-converted into a signal that can be collected by the quantum analyzer 3, such as an intermediate frequency signal (with a frequency of several hundred MHz). When there is a problem with the signal transmitted by the first arbitrary waveform generator 6, or when there is a problem with the first IQ mixer 7, or when the microwave source 8 does not transmit normally, the host computer connected to the quantum analyzer 3 can be informed in real time.

[0197] The process of real-time monitoring of the above-mentioned signal and the process of calibrating the first IQ mixing component are two independent processes, which are implemented through the hardware architecture of the same measurement and control system.

[0198] Example 2:

[0199] In the second embodiment of the present invention, for a multi-bit measurement and control circuit, it is necessary to expand and integrate the structure of the measurement and control system of the above-mentioned first embodiment.

[0200] Accordingly, refer to Figure 4 As shown, the control signal monitoring unit 2 specifically includes: a first signal distribution module 9, a first combiner 10 and a demodulation mixer 5; wherein:

[0201] The first combiner 10 is provided between the first signal distribution module 9 and the demodulation mixer 5;

[0202] The first signal distribution module 9 includes a plurality of first signal distribution devices 4; the plurality of first signal distribution devices 4 are connected to the first combiner 10;

[0203] A plurality of first signal distribution devices 4 are respectively connected to the multi-channel output terminals of the control signal generating unit 1; each of the first signal distribution devices 4 is used to couple out a portion of the control signal of the corresponding channel;

[0204] A first combiner 10 is used to combine the signals obtained by coupling of the plurality of first signal distribution devices 4 and output the combined signals;

[0205] The demodulation mixer 5 is used to demodulate the signal output after the combination of the first combiner 10 and input the demodulated signal into the quantum analyzer 3 .

[0206] Similar to the first embodiment, the first signal distribution device 4 may be implemented, for example, by a power splitter or a directional coupler.

[0207] Correspondingly, the first waveform generating component 27 is the first arbitrary waveform generating module 11; the first IQ mixing component 28 is the first IQ mixing module 12; the control signal generating unit further includes: a microwave source 8;

[0208] The input end of the demodulation mixer 5 is respectively connected to the quantum processing unit 22, the output end of the first combiner 10 and the microwave source 8, and the output end of the demodulation mixer 5 is connected to the quantum analyzer 3;

[0209] The first arbitrary waveform generating module 11 includes a plurality of first arbitrary waveform generators 6; or the first arbitrary waveform generating module 11 includes a first arbitrary waveform generator 6 with a multi-channel output terminal;

[0210] A first IQ mixing module 12, comprising a plurality of first IQ mixers 7;

[0211] The first arbitrary waveform generator 6 in the first arbitrary waveform generating module 11 is configured to transmit a baseband signal to the first IQ mixer 7 in the first IQ mixing module 12;

[0212] The microwave source 8 is used to output a local oscillator signal to the first IQ mixer 7 in the first IQ mixing module 12;

[0213] The first IQ mixer 7 is used to mix the baseband signal and the local oscillator signal and output the first signal to the first signal distribution device 4;

[0214] The multiple first IQ mixers 7 in the first IQ mixing module 12 are respectively connected to the multiple first arbitrary waveform generators 6 in the first arbitrary waveform generating module 11 and the output ends of the multi-channel microwave source 8 to form multiple control signal generation channels (corresponding to the case where the first arbitrary waveform generating module 11 includes multiple first arbitrary waveform generators 6); wherein the input end of each first IQ mixer 7 is respectively connected to the output end of the microwave source 8 and the first arbitrary waveform generator 6 of the same channel; and the output end of each first IQ mixer 7 is respectively connected to the input end of the first signal distribution device 4 of the same channel of the first signal distribution module 9;

[0215] Alternatively, the multiple first IQ mixers 7 in the first IQ mixing module 12 may be connected to the first arbitrary waveform generating module 11 and the microwave source 8 in the following manner: the multiple first IQ mixers 7 in the first IQ mixing module 12 are respectively connected to the multi-channel output ends of the first arbitrary waveform generating module 11 and the multi-channel output ends of the microwave source 8, so as to form multiple control signal generation channels (corresponding to the case where the first arbitrary waveform generating module 11 includes a first arbitrary waveform generator 6 having a multi-channel output end).

[0216] The microwave source 8 is used to output a local oscillator signal for demodulation to the demodulation mixer 5 .

[0217] In the second embodiment of the present invention, when the first combiner 10 is used to combine multiple control signals, the microwave source 8 outputs a local oscillator signal for demodulation, that is, each control signal is demodulated using the same local oscillator signal.

[0218] The demodulation mixer 5 is specifically used to mix the signal output by the first combiner 10 with the local oscillator signal of the control signal for demodulation output by the microwave source 8, and down-convert it into a signal that can be collected and analyzed by the quantum analyzer.

[0219] Figure 4In the system architecture shown, since multiple control signal transmission channels are required, the above-mentioned first arbitrary waveform generating module 11 may include multiple first arbitrary waveform generators 6, each of which corresponds to one channel; or the first arbitrary waveform generating module 11 itself includes a first arbitrary waveform generator 6 with multi-channel output, and the multiple output channels of the first arbitrary waveform generator 6 correspond to the multiple control signal transmission channels.

[0220] On the same channel, an output of a first arbitrary waveform generator 6 is connected to an input of a first IQ mixer 7 , and another input of the first IQ mixer 7 is connected to an output of a microwave source 8 .

[0221] On the same channel, the output of the first IQ mixer 7 is connected to the input of a first signal distribution device 4 .

[0222] In this way, the first combiner 10 will have multi-channel inputs, and the first combiner 10 will combine the multi-channel signals and output them. In this way, each channel uses a corresponding first signal distribution device 4 (such as a directional coupler or power splitter). The signals coupled from the multiple first signal distribution devices 4 are all combined through the first combiner 10, and then the same microwave source 8 is used for down-conversion to obtain a signal that can be collected and analyzed by the quantum analyzer 3. This architecture not only realizes the expansion and integration of multi-bit measurement and control circuits, but also reduces the hardware requirements of the microwave source 8 channels, simplifying the structure while saving hardware costs.

[0223] Figure 4 The system architecture shown has e.g. Figure 3 The single-channel system architecture shown has similar features and advantages, such as the ability to monitor multi-channel AWG transmission signals, calibrate multi-channel first IQ mixers, and monitor whether there are problems with multi-channel high-frequency lines.

[0224] Since the first arbitrary waveform generating module includes several first arbitrary waveform generators, the first IQ mixing module also includes multiple first IQ mixers. Since a first arbitrary waveform generator (or an output channel of the first arbitrary waveform generator) and a first IQ mixer and a channel of the microwave source constitute a control signal generation channel, the calibration process of each first IQ mixer in the first IQ mixing module of the multi-bit measurement and control circuit of Example 2 is similar to the calibration process of the single first IQ mixer in Example 1. Moreover, the calibration process of each first IQ mixer can be performed independently. Reference can be made to the implementation process of Example 1, and no further details are given here.

[0225] For the same control signal generation channel, the calibration process for the first IQ mixer involves the first arbitrary waveform generator (AWG) that transmits the baseband signal. This means that the first AWG in that control signal generation channel executes the first scan instruction and ultimately adjusts the baseband signal to the first optimal parameters. The calibration process for different first IQ mixers is independent of the first AWGs in other channels.

[0226] In the second embodiment, the process of the measurement and control system of the quantum computer performing real-time monitoring of the control signal is briefly described as follows:

[0227] The first arbitrary waveform generator 6 in the first arbitrary waveform generation module 11 transmits the required multiple baseband signals (IQ signals), which are input to the first IQ mixing module 12. In the first IQ mixing module 12, each first IQ mixer 7 mixes the signals with the microwave signal output by the microwave source 8 to generate a high-frequency signal. After the first signal distribution devices 4 in the first signal distribution module 9 couple a portion of the signal, the signals are combined to form a control signal. The combined control signal is then input to the demodulation mixer 5, where it is mixed with the microwave signal output by the microwave source 8 and down-converted into a signal that can be collected by the quantum analyzer 3, such as an intermediate frequency signal (with a frequency of several hundred MHz). If there is a problem with the signal emitted by the first arbitrary waveform generation module 11, or if there is a problem with the first IQ mixing module 12, or if the microwave source 8 is not transmitting properly, the host computer connected to the quantum analyzer 3 can be notified in real time. In the above-mentioned second embodiment, the microwave signal output by the microwave source 8 to the first IQ mixing module 12 is the same as the microwave signal output to the demodulation mixer 5.

[0228] Example 3:

[0229] The above-mentioned first and second embodiments both illustrate technical solutions for real-time monitoring of the control signal channel and calibration of the first IQ mixing component in the control signal channel. In the third embodiment of the present invention, in addition to the above-mentioned improvements to the control signal channel, the same or similar improvements may optionally be made to the read signal channel.

[0230] The structure of a quantum computer's measurement and control system with improvements to both the control signal path and the read signal path can be found in Figure 2 and Figure 5 shown.

[0231] As mentioned above, for the convenience of explanation, in the above-mentioned embodiments 1 and 2, the components in the control signal path are all referred to with the prefix "first", such as the first signal distribution device, the first arbitrary waveform generator, the first IQ mixer, etc. In the third embodiment of the present invention, the components for the control signal path are still the same as those in the first and second embodiments, while the components for the read signal path are referred to with the prefix "second". The above-mentioned "first" and "second" are only for distinguishing different components.

[0232] Components not distinguished by "first" and "second" mean components that are shared by both the control signal path and the read signal path.

[0233] For the structure and function of the control signal channel of the third embodiment (the structure and function of the first waveform generating component 27, the first IQ mixing component 28, the first arbitrary waveform generator 6, the first IQ mixer 7, the first signal distribution device 4, the demodulation mixing module 16, etc. in the real-time monitoring of the control signal and the calibration scheme of the first IQ mixing component), reference may be made to the description of the aforementioned first and second embodiments, and no further details are given here.

[0234] Reference Figure 2 and Figure 5 As shown, the measurement and control system of the quantum computer can further include a read-in signal generating unit 25 and a read-in signal monitoring unit 26 based on the relevant structures of the control paths of the above-mentioned embodiment 1 and embodiment 2.

[0235] The read signal generating unit 25 is used to generate a read signal to the quantum processing unit of the quantum computer to read the state of the quantum bit in the quantum processing unit; the read signal generating unit 25 includes: a second waveform generating component 29 and a second IQ mixing component 30; the second waveform generating component 29 is used to transmit the baseband signal of the read signal to the second IQ mixing component 30;

[0236] In the third embodiment of the present invention, continue to refer to Figure 5 As shown, the second IQ mixing component may be, for example, a second IQ mixer 14; the second waveform generating component may be, for example, a second arbitrary waveform generator 13;

[0237] The read-in signal monitoring unit 26 is used to couple out a portion of the read-in signal generated by the read-in signal generating unit 25, output it to the quantum analyzer 3 after demodulation, and output the remaining read-in signal to the quantum processing unit 22;

[0238] The host computer 20 also communicates with the second waveform generating component 29 (for example Figure 5 A second arbitrary waveform generator 13) is connected;

[0239] The host computer 20 is further configured to send a second scanning instruction to the second waveform generating component 29 (e.g., the second arbitrary waveform generator 13); and determine a second optimal parameter for sideband suppression of the second waveform generating component 29 (e.g., the second arbitrary waveform generator 13) based on the frequency domain information obtained by the quantum analyzer; and return the second optimal parameter to the second waveform generating component so that the second waveform generating component 29 (e.g., the second arbitrary waveform generator 13) can transmit a baseband signal corresponding to the second optimal parameter, and correct the second IQ mixing component 30 (e.g., Figure 5 The deviation of the second IQ mixer 14 in FIG;

[0240] A second waveform generating component 29 (e.g., a second arbitrary waveform generator 13), configured to sequentially transmit baseband signals corresponding to different independent variable sizes according to the second scanning instruction;

[0241] The quantum analyzer 3 is used to collect and perform frequency domain analysis on the signal output by the signal monitoring unit 26 during the execution of the second scanning instruction by the second waveform generating component 29 (for example, the second arbitrary waveform generator 13), and output the frequency domain information obtained by the analysis to the host computer 20.

[0242] The calibration process of the above-mentioned second IQ mixing component 30 is similar to the calibration process of the first IQ mixing component 28 in Example 1. The difference is that the baseband signals transmitted by the first waveform generating component 27 and the second waveform generating component 29 are different. The first waveform generating component 27 is a baseband signal for generating a control signal, and the second waveform generating component 29 transmits a baseband signal for generating a read signal.

[0243] Correspondingly, the host computer 20 is specifically used to generate a heat map based on the frequency domain information obtained by the quantum analyzer 3; and determine the second optimal parameters of the sideband suppression of the second waveform generating component 29 (such as the second arbitrary waveform generator 13) based on the heat map.

[0244] The host computer 20 is further configured to use the spectrum amplitude of the signal collected by the quantum analyzer 3 as a dependent variable corresponding to the independent variable, draw a heat map, identify points that meet the principles of the highest amplitude of the read signal, the lowest amplitude of the local oscillator leakage, and the lowest amplitude of the image frequency signal, and determine the second optimal parameter based on one or more of the relative amplitude, phase, and offset of the identified points.

[0245] The quantum analyzer 3 is specifically used to collect the signal output by the second waveform generating component 29 (for example, the second arbitrary waveform generator 13) during the execution of the scanning instruction, read the signal output by the signal monitoring unit 26, perform Fourier transform to obtain the corresponding frequency domain signal, obtain the frequency domain information of the frequency domain signal, and output it to the host computer 20.

[0246] Read the signal output by the signal monitoring unit 26, that is, Figure 5 The signal output by the demodulation mixing module 16 in the signal monitoring unit is read in.

[0247] When the quantum computer is, for example, a superconducting quantum computer, the read-in signal is a microwave signal whose frequency is equal to the frequency of the measurement resonant cavity used to read the quantum bit state. The quantum bit state can be determined based on the change in the read-out signal output by the quantum processing unit 22 relative to the read-in signal. The frequency range of the read-in signal is, for example, 4 GHz to 8 GHz. It is understood that when the quantum computer is a suitable type of quantum computer other than a superconducting quantum computer, the read-in signal may also correspond to a signal of other frequencies, and this application is not limited to this.

[0248] In a superconducting quantum computer, reading the state of a qubit is usually achieved through a measurement resonant cavity (also called a readout resonant cavity) coupled to the qubit.

[0249] The measurement cavity is a microwave resonator whose frequency is designed to be related to the state of the qubit. When the state of the qubit is to be read, a microwave signal of a specific frequency is sent to the measurement cavity—this is the so-called "read signal." The frequency of this signal is usually set to equal the frequency of the cavity.

[0250] If the qubit is in the "|0>" state, the cavity's response will be different from when it is in the "|1>" state. By measuring the cavity's response (for example, the amplitude or phase change of the microwave signal), the qubit's state can be determined.

[0251] This readout strategy is based on the "weak measurement" principle of quantum mechanics and aims to minimize the interference of the measurement process on the quantum bit state.

[0252] In the measurement and control system 24 of the quantum computer provided in an embodiment of the present invention, a read-in signal monitoring unit 26 is connected between the read-in signal generating unit 25 and the quantum analyzer 3. The read-in signal monitoring unit 26 couples a portion of the read-in signal, demodulates it, and outputs it to the quantum analyzer 3, which then collects and analyzes the signal. This allows real-time monitoring of the read-in signal, improving monitoring efficiency. Furthermore, since the connection relationship of the quantum computer's measurement and control system 24 does not need to be changed during the monitoring process, the risk of incorrect connection of the post-inspection restoration circuit is avoided. Furthermore, based on the aforementioned architecture for monitoring the read-in signal, it is also convenient to utilize the second arbitrary waveform generator 13 to execute the scanning command issued by the host computer 20. The host computer 20 finds the second optimal parameters and returns them to the second arbitrary waveform generator 13. The baseband signal is then transmitted according to the second optimal parameters to calibrate the second IQ mixer 14.

[0253] Specifically, the above-mentioned read-in signal monitoring unit 26 specifically includes: a second signal distribution device 15 and a demodulation mixing module 16;

[0254] Because a single demodulation mixer can usually only process one signal (control signal or read signal), the above-mentioned read signal monitoring unit 26 and the control signal monitoring unit 2 respectively use corresponding demodulation mixers for demodulation. In specific implementation, from a hardware perspective, the demodulation mixer corresponding to the read signal monitoring unit 26 and the demodulation mixer corresponding to the control signal monitoring unit 2 can be integrated into the same module, namely the above-mentioned demodulation mixing module 16.

[0255] a second signal distribution device 15 connected between the read-in signal generating unit 25 and the quantum processing unit 22, configured to couple out a portion of the read-in signal generated by the read-in signal generating unit 25 and output it to the demodulation mixing module 16, and output the remaining read-in signal to the quantum processing unit 22;

[0256] The input end of the demodulation mixing module 16 is connected to the second signal distribution device 15 and the read-in signal generating unit 25 respectively, and the output end of the demodulation mixing module 16 is connected to the quantum analyzer 3;

[0257] The demodulation mixing module 16 is further used to demodulate the read signal coupled from the second signal distribution device 15 and output it to the quantum analyzer 3;

[0258] Correspondingly, the quantum analyzer 3 is also used to collect and analyze the read-in signal demodulated by the demodulation mixing module 16, so as to monitor the read-in signal, calibrate the second IQ mixer, or monitor the relative order of the control signal and the read-in signal.

[0259] Furthermore, the read-in signal generating unit 25 includes, in addition to the second arbitrary waveform generator 13 and the second IQ mixer 14, a microwave source 8; wherein:

[0260] A second arbitrary waveform generator 13, configured to transmit a baseband signal to the second IQ mixer;

[0261] The read-in signal generating unit 25 and the control signal generating unit 1 share the same microwave source 8;

[0262] The second IQ mixer 14 is used to mix the baseband signal and the local oscillator signal and output the second signal to the second signal distribution device 15;

[0263] Sharing the same microwave source 8 can save hardware costs. In some possible embodiments, the read signal generating unit 25 and the control signal generating unit 1 may not share the same microwave source 8, but use their own microwave sources 8, which is not limited in the embodiment of the present invention.

[0264] Similar to the path of the control signal, the microwave source 8 is used to provide a microwave signal (local oscillator signal) to the second IQ mixer 14 and the demodulation mixing module 16 .

[0265] Reference Figure 5 As shown, the input end of the demodulation mixing module 16 is respectively connected to the quantum processing unit 22, the output end of the first signal distribution device 4, the output end of the second signal distribution device 15 and the microwave source 8, and the output end of the demodulation mixing module 16 is connected to the quantum analyzer 3.

[0266] The demodulation mixer in the demodulation mixing module 16 is specifically used to mix the read signal coupled by the second signal distribution device 15 with the local oscillator signal output by the microwave source 8, down-convert it into a signal that can be collected and analyzed by the quantum analyzer 3, and output it to the quantum analyzer 3.

[0267] In the third embodiment, during the real-time signal monitoring process, the microwave signal output by the microwave source 8 to the second IQ mixer 14 is the same as the microwave signal output to the demodulation mixing module 16 .

[0268] The second signal distribution device 15 can be implemented, for example, as a power splitter or a directional coupler. However, the second signal distribution device 15 can also be other suitable electronic devices. For the structure and corresponding functions of the power splitter and directional coupler, please refer to the description of the first embodiment.

[0269] Similar to the first embodiment, in some embodiments, the quantum analyzer 3 can collect and perform simple analysis on the demodulated read signal, and then output it to the upper-level host computer 20 connected to the quantum analyzer 3 for further analysis and logical judgment to determine whether the read signal is correct, whether the order of the control signal and the read signal is correct, etc.

[0270] In some other embodiments, the quantum analyzer 3 itself has complex analysis and judgment functions. After collecting and analyzing the demodulated read-in signal, it can directly perform further analysis and judgment to determine whether the read-in signal is correct, whether the order of the control signal and the read-in signal is correct, etc.

[0271] It should be noted that if only a single path is involved, such as only the improvement of the control signal path, a single demodulation mixer 5 can be used. However, if both the control signal path and the read signal path are involved, the demodulation mixing module 16 includes multiple demodulation mixers 5 to respectively realize the demodulation of the control signal and the read signal.

[0272] exist Figure 5 In the embodiment, the host computer 20 interacts with the microwave source 8, the first arbitrary waveform generator 6, the second arbitrary waveform generator 13 and the quantum analyzer 3 through the switch 21. In some embodiments, the host computer 20 can also interact with these devices directly without going through network devices such as switches, or can interact with these devices through other suitable devices such as USB interfaces.

[0273] In the measurement and control system 24 of the quantum computer provided in the embodiment of the present invention, a second signal distribution device 15 is provided between the second IQ mixer 14 and the quantum processing unit 22. After the baseband signal emitted by the second arbitrary waveform generator 13 is mixed with the local oscillator signal (also called microwave signal) emitted by the microwave source 8, before entering the quantum processing unit 22, the second signal distribution device 15 can couple out a portion of the read signal, and a portion of the read signal enters the quantum processing unit 22. The coupled read signal is connected to the demodulation mixing module 16, mixed with the microwave signal output by the microwave source 8, and down-converted into a signal that can be collected by the quantum analyzer 3, such as an intermediate frequency signal (frequency of several hundred MHz). Since the microwave source 8 provides the same frequency, The microwave signal up-converts the baseband signal output by the second arbitrary waveform generator 13 and down-converts the read signal output by the second IQ mixer 14. Therefore, the signal sampled by the quantum analyzer 3 and the signal emitted by the second arbitrary waveform generator 13 have the same frequency and timing. Although there may be some amplitude variations, they are completely linearly aligned. This ensures the consistency of the monitored read signal with the baseband signal originally emitted by the second arbitrary waveform generator 13, enabling real-time monitoring of the signal originally emitted by the second arbitrary waveform generator 13 and improving monitoring efficiency. Furthermore, since the connection relationship of the quantum computer's measurement and control system does not need to be changed during the monitoring process, the risk of incorrect connection of the recovery circuit after inspection is avoided.

[0274] It should be noted that, unlike the process of real-time monitoring of the signal, in the process of calibrating the second IQ mixer, similar to Example 1, demodulation and modulation need to be implemented using carriers of different frequencies. For example, the second arbitrary waveform generator 13 transmits a 100 MHz IQ signal, and in the second IQ mixer, the 100 MHz IQ signal is mixed with the 5 GHz Lo (local oscillator signal) to generate three signals of 5.1 GHz (read-in signal), 5 GHz (local oscillator leakage), and 4.9 GHz (mirror image, which needs to be suppressed). Then, after passing through the second signal distribution device 15, it is necessary to use the 4.99 GHz local oscillator signal Lo for demodulation to generate three signals of 110 MHz (corresponding to the read-in signal), 10 MHz (corresponding to the local oscillator leakage), and 90 MHz (corresponding to the mirror image). After the quantum analyzer collects the signals and performs Fourier transform, the corresponding frequency domain information can be obtained. The relative amplitude, phase and offset of the IQ signal are scanned as independent variables. The size of the independent variable is changed with a set step size during the scan. The spectrum amplitude of the collected signal is used as the dependent variable to draw a heat map, and the second optimal parameter for IQ signal sideband suppression can be obtained.

[0275] At this time, the microwave source needs to include at least two channels with different carrier frequencies; during the calibration process of the second IQ mixer 14, local oscillator signals with different carrier frequencies of the microwave source are used for modulation and demodulation respectively.

[0276] Example 4:

[0277] For the structure and function of the control signal channel of the fourth embodiment (the structure and function of the first arbitrary waveform generating module 11, the first IQ mixing module 12, the first signal distribution module 9, the demodulation mixing module 16, etc. in the scheme for monitoring the control signal), reference can be made to the description of the aforementioned first and second embodiments, and no further details will be given here.

[0278] Similar to the second embodiment, for the multi-bit measurement and control circuit, it is necessary to expand and integrate the structure of the third embodiment, and improve both the control signal channel and the read signal channel. In addition to the relevant components for monitoring the control signal, refer to Figure 6 As shown, the input signal monitoring unit 26 of the measurement and control system of the quantum computer includes: a second signal distribution module 23, a second combiner 19 and a demodulation mixing module 16;

[0279] The second combiner 19 is provided between the second signal distribution module 23 and the demodulation mixing module 16;

[0280] The second signal distribution module 23 includes a plurality of second signal distribution devices 15; the plurality of second signal distribution devices 15 are connected to the second combiner 19;

[0281] A plurality of second signal distribution devices 15 are respectively connected to the multi-channel output terminals of the read signal generating unit 25; each second signal distribution device 15 is used to couple out a portion of the read signal of the corresponding channel;

[0282] The second combiner 19 is used to combine the signals coupled by the plurality of second signal distribution devices 15 and output the combined signals;

[0283] The demodulation mixer 5 is used to demodulate the signal output after the second combiner 19 combines and then input it into the quantum analyzer 3 .

[0284] Specifically, the read-in signal generating unit 25 includes: a second arbitrary waveform generating module 17, a second IQ mixing module 18 and a microwave source 8;

[0285] The read-in signal generating unit 25 and the control signal generating unit 1 share the same microwave source 8;

[0286] Similar to the aforementioned third embodiment, the read-in signal generating unit 25 and the control signal generating unit 1 do not need to share the same microwave source 8 .

[0287] Similarly, the second arbitrary waveform generator 13 is configured to transmit a baseband signal to the second IQ mixer; and during calibration of the second IQ mixer, sequentially transmit baseband signals corresponding to different independent variable sizes (for generating a read signal) according to a second scanning instruction issued by the host computer 20;

[0288] The second IQ mixer 14 is used to mix the baseband signal and the local oscillator signal and output the second signal to the second signal distribution device 15;

[0289] The input end of the demodulation mixing module 16 is connected to the quantum processing unit 22, the output end of the second combiner 19 and the microwave source 8 respectively, and the output end of the demodulation mixing module 16 is connected to the quantum analyzer 3;

[0290] A second arbitrary waveform generating module 17, comprising a plurality of second arbitrary waveform generators 13;

[0291] A second IQ mixing module 18, comprising a plurality of second IQ mixers 14;

[0292] The multiple second IQ mixers 14 in the second IQ mixing module 18 are respectively connected to the multiple second arbitrary waveform generators 13 in the second arbitrary waveform generating module 17 and the output ends of the multi-channel microwave source 8 to form multiple read-in signal generation channels; wherein the input end of each second IQ mixer 14 is respectively connected to the output end of the microwave source 8 and the second arbitrary waveform generator 13 of the same channel; and the output end of each second IQ mixer 14 is respectively connected to the input end of the second signal distribution device 15 of the same channel of the second signal distribution module 23;

[0293] A microwave source 8 is used to output a local oscillator signal for demodulating the input signal to the demodulation mixing module 16;

[0294] The host computer 20 is configured to send a first scan instruction to the second arbitrary waveform generator 13 in the second arbitrary waveform generation module 17 during the second IQ mixer calibration process; determine a first optimal parameter for sideband suppression of the second arbitrary waveform generator 13 based on frequency domain information obtained by the quantum analyzer; and return the first optimal parameter to the second arbitrary waveform generator 13, so that the second arbitrary waveform generator 13 can transmit a baseband signal (IQ signal) corresponding to the first optimal parameter to correct the deviation of the second IQ mixer in the same input signal generation channel.

[0295] In one embodiment of the present invention, the second arbitrary waveform generation module 17 includes multiple second arbitrary waveform generators 13, and the second IQ mixing module 18 includes multiple second IQ mixers 14. The multiple second IQ mixers 14 in the second IQ mixing module 18 are respectively connected to the multiple second arbitrary waveform generators 13 in the second arbitrary waveform generation module 17 and the multi-channel output ends of the microwave source 8 to form multiple input signal generation channels. For a single input signal generation channel, the calibration process of its second IQ mixer 14 is similar to that of the third embodiment. Moreover, the calibration process of the second IQ mixers 14 in different input signal generation channels is independent of each other and only involves the second arbitrary waveform generation module 17 in the same generation channel. The specific calibration process can be referred to the implementation process of the aforementioned first to third embodiments and will not be repeated here.

[0296] For the same input signal generation channel, the calibration process for the second IQ mixer involves the second arbitrary waveform generator (AWG) that transmits the baseband signal. This means that the second scan instruction is executed by the second AWG in the control signal generation channel, and ultimately, the baseband signal is adjusted by this second AWG. The calibration process for different second IQ mixers is independent of the second AWGs in other input signal generation channels.

[0297] In the real-time monitoring process, although multiple channels of input signals are involved, the demodulation mixing module uses the same local oscillator signal to demodulate the input signals of multiple channels.

[0298] The demodulation mixing module 16 is specifically used to mix the signal output after the second combiner 19 is combined with a local oscillator signal for demodulating the read signal, and down-convert it into a signal that can be collected and analyzed by the quantum analyzer;

[0299] The quantum analyzer 3 is further configured to collect and analyze the read-in signal demodulated by the demodulation mixing module 16, so as to monitor the read-in signal and / or monitor the relative sequence of the control signal and the read-in signal.

[0300] Similar to the second embodiment, the second arbitrary waveform generating module 17 may further include a second arbitrary waveform generator 13 ( Figure 6 Although only one second arbitrary waveform generator 13 is used, the plurality of second IQ mixers 14 in the second IQ mixing module 18 are respectively connected to the multi-channel output end of the second arbitrary waveform generating module 17 and the multi-channel output end of the microwave source 8 to form a plurality of read-in signal generating channels. The specific structure can be referred to Figure 6 shown.

[0301] Figure 6 In the system architecture shown, since multiple transmission channels for reading in signals are required, correspondingly, the second arbitrary waveform generating module 17 may include multiple second arbitrary waveform generators 13 ( Figure 6 (not shown), each second arbitrary waveform generator 13 corresponds to a channel; or the second arbitrary waveform generating module 17 itself includes a second arbitrary waveform generator 13 with multi-channel output, and the multiple output channels of the second arbitrary waveform generator 13 correspond to the sending channels of the multiple read-in signals.

[0302] On the same read-in signal channel, the output of a second arbitrary waveform generator 13 is connected to the input of a second IQ mixer 14 , and the other input of the second IQ mixer 14 is connected to the output of the microwave source 8 .

[0303] On the same channel, the output of the second IQ mixer 14 is connected to the input of a second signal distribution device 15 .

[0304] In this way, second combiner 19 receives input signals from multiple channels, combines them, and outputs them. Each channel uses a corresponding second signal distribution device 15, and all signals coupled from the multiple second signal distribution devices 15 are combined by second combiner 19. The signals are then down-converted using the same microwave source 8, resulting in a signal that can be collected and analyzed by quantum analyzer 3. This architecture not only expands and integrates multi-bit measurement and control circuits for the input signals, but also reduces the hardware requirements for the microwave source 8 channels, simplifying the structure while saving hardware costs.

[0305] The process of real-time monitoring of the input signal by the measurement and control system of the quantum computer is briefly described as follows:

[0306] The second arbitrary waveform generator 13 in the second arbitrary waveform generation module 17 transmits the required multiple baseband signals, which are then input into the second IQ mixer module 18. Within the second IQ mixer module 18, each second IQ mixer 14 mixes the signals with the microwave signal output by the microwave source 8 to generate a high-frequency signal. After the second signal distribution devices 15 in the second signal distribution module 23 couple out a portion of the signal, the signals are combined to form a single read signal. The combined read signal is then connected to the demodulation mixer module 16, where it is mixed with the microwave signal output by the microwave source 8 and down-converted into a signal that can be collected by the quantum analyzer 3. If there is a problem with the signal emitted by the second arbitrary waveform generation module 17, the second IQ mixer module 18, or the microwave source 8 is not transmitting properly, the host computer connected to the quantum analyzer 3 can be notified in real time. In the above-described second embodiment, the microwave signal output by the microwave source 8 to the second IQ mixer module 18 is the same as the microwave signal output to the demodulation mixer module 16.

[0307] The above-mentioned embodiments 3 and 4 are improvements for both the control signal channel and the read signal channel, thereby realizing real-time monitoring of the control signal and / or the read signal, and monitoring whether the transmission sequence of the two is abnormal; and realizing calibration of the first IQ mixing component in the control signal generation channel and / or the second IQ mixing component in the read signal generation channel.

[0308] Those skilled in the art will appreciate, based on the descriptions of Examples 1 to 4 above, that the improvements to the control signal channel in this application are similar to those to the read signal channel. In specific implementations, improvements can be made only to the control signal channel to enable real-time monitoring of only the control signal and calibration of only the first IQ mixing component in the control signal generation channel. Alternatively, improvements can be made only to the read signal channel to enable real-time monitoring of only the read signal and calibration of only the second IQ mixing component in the read signal generation channel. Alternatively, improvements can be made to both channels simultaneously to enable monitoring of both channels and calibration of the mixing components in both channels. For various possible implementations, reference can be made to the description of the structures and principles of the aforementioned embodiments.

[0309] In the third and fourth embodiments described above, the host computer 20 is connected to the microwave source 8 via the switch 21. Furthermore, the host computer 20 is connected to the first arbitrary waveform generator 6 (or the first arbitrary waveform generating module 11), the second arbitrary waveform generator 13 (or the second arbitrary waveform generating module 17), and the quantum signal analyzer 3 via the switch 21. In a possible embodiment, the host computer 20 may be directly connected to these devices without passing through the switch 21. The switch 21 may also be other replaceable network devices that only need to implement the communication function.

[0310] In the third and fourth embodiments above, during the real-time signal monitoring process, the microwave signal output by the microwave source 8 to the second IQ mixer 14 or the second IQ mixing module 18 is the same as the microwave signal output to the demodulation mixing module 16 .

[0311] Similar to the third embodiment, during the calibration of the second IQ mixer 14, demodulation (implemented by the demodulation mixing module 16) and modulation (implemented by the second IQ mixer 14) require the use of local oscillator signals of different carrier frequencies of the microwave source 8. For the specific implementation method, please refer to the third embodiment.

[0312] In the above-mentioned third and fourth embodiments, the second signal distribution device 15 may also be, for example, a power splitter or a directional coupler.

[0313] The above embodiment 3 Figure 5 and Example 4 Figure 6 In the quantum processing unit, the Z signal determines the operating frequency of the quantum bit. When the frequency of the XY signal is equal to the operating frequency of the quantum bit, the quantum bit will be excited. The read-in signal and the read-out signal are used to obtain the state of the quantum bit.

[0314] It can be understood that in the above-mentioned second and fourth embodiments, control signals and read-in signals of multiple channels can also be demodulated using multiple local oscillator signals, which is also possible.

[0315] The measurement and control systems of the above-mentioned embodiments of the present application are measurement and control systems for quantum computers. Preferably, the quantum computer is a superconducting quantum computer, and accordingly, the quantum processing unit 22 is a superconducting quantum chip. However, the quantum computer can also be any suitable quantum computer such as an ion trap quantum computer, a photon quantum computer, a topological quantum computer, a neutral atom quantum computer, a silicon-based quantum computer, or a nuclear magnetic resonance quantum computer. As long as it is an improvement idea or improvement scheme based on the measurement and control system of the quantum computer of the present invention, it should fall within the scope of protection of this application. It should be noted that for quantum computers of different systems, the structure, principle, state, etc. of the quantum processing unit 22 may be different, but they are all processing units with quantum bits.

[0316] Based on the same inventive concept, embodiments of the present invention further provide a quantum computer and a method for calibrating an IQ mixing component. Since the principles of the problems solved by the quantum computer and the method for calibrating the IQ mixing component are similar to those of the aforementioned measurement and control system of the quantum computer, the implementation of the quantum computer and the method for calibrating the IQ mixing component can refer to the implementation of the aforementioned system, and the repeated parts will not be repeated.

[0317] A quantum computer provided by an embodiment of the present invention, referring to Figure 7As shown, it includes: the measurement and control system 24 of the quantum computer and the quantum processing unit 22 as mentioned above;

[0318] The control signal monitoring unit 2 in the measurement and control system is connected to the quantum processing unit 22, and is used to couple out a portion of the control signal emitted by the control signal generating unit 1 in the measurement and control system, output it to the quantum analyzer 3 after demodulation for collection and analysis, and output the remaining control signal to the quantum processing unit 22 for controlling the quantum bit.

[0319] The specific implementation of the measurement and control system 24 for achieving real-time monitoring and calibration of the IQ mixer can be found in the aforementioned embodiment and will not be described in detail here.

[0320] Reference Figure 8 As shown, the method for calibrating the IQ mixing component in the measurement and control system of the quantum computer provided in an embodiment of the present invention includes the following steps:

[0321] S81, the host computer sends a first scanning instruction to the first waveform generating component in the control signal generating unit;

[0322] S82: The first waveform generating component sequentially transmits IQ signals corresponding to different independent variable sizes according to the first scanning instruction;

[0323] S83: The quantum analyzer collects the signal output by the control signal monitoring unit during the execution of the first scanning instruction by the first waveform generating component, performs frequency domain analysis on the signal, and outputs the obtained frequency domain information to the host computer;

[0324] S84. The host computer determines a first optimal parameter for sideband suppression of the first waveform generating component based on the frequency domain information obtained by the quantum analyzer; and returns the first optimal parameter to the first waveform generating component, so that the first waveform generating component can transmit a baseband signal corresponding to the first optimal parameter to correct the deviation of the first IQ mixing component.

[0325] Furthermore, based on the architecture of the aforementioned third and fourth embodiments, the embodiment of the present invention can also implement calibration of the second IQ mixing component in the read-in signal generation channel, specifically in the following manner:

[0326] The host computer sends a second scanning instruction to the second waveform generating component in the read-in signal generating unit;

[0327] The second waveform generating component sequentially transmits IQ signals corresponding to different independent variables according to the second scanning instruction;

[0328] The quantum analyzer collects the signal output by the control signal monitoring unit during the execution of the second scanning instruction by the first waveform generating component and performs frequency domain analysis, and outputs the frequency domain information obtained by the analysis to the host computer;

[0329] The host computer determines the second optimal parameters for sideband suppression of the second waveform generating component based on the frequency domain information obtained by the quantum analyzer; and returns the second optimal parameters to the second waveform generating component, so that the second waveform generating component can transmit a baseband signal corresponding to the second optimal parameters and correct the deviation of the second IQ mixing component.

[0330] The specific calibration method of the first IQ mixing component in the control signal generating channel and the second IQ mixing component in the read signal generating channel can refer to the specific processes of the above-mentioned embodiments 1 to 4, and will not be repeated here.

[0331] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) containing computer-usable program code.

[0332] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0333] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0334] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0335] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A measurement and control system for a quantum computer, characterized in that: include: Control signal generating unit, control signal monitoring unit, quantum analyzer, and host computer; The control signal generating unit is used to generate a control signal for manipulating the quantum bits in the quantum processing unit of the quantum computer; The control signal generating unit includes: a first waveform generating component and a first IQ mixing component; the first waveform generating component is used to transmit a baseband signal of the control signal to the first IQ mixing component; The input end of the control signal monitoring unit is connected to the control signal generating unit, and the output end is connected to the quantum analyzer and the quantum processing unit respectively; the control signal monitoring unit is used to couple out part of the control signal generated by the control signal generating unit, output it to the quantum analyzer after demodulation, and output the remaining control signal to the quantum processing unit to control the quantum bit; The host computer is connected to the quantum analyzer and the first waveform generating component respectively; The host computer is configured to send a first scanning instruction to the first waveform generating component; and determine a first optimal parameter for sideband suppression of the first waveform generating component based on frequency domain information obtained by the quantum analyzer; and return the first optimal parameter to the first waveform generating component, so that the first waveform generating component can transmit a baseband signal corresponding to the first optimal parameter, and correct the deviation of the first IQ mixing component; The first waveform generating component is configured to sequentially transmit baseband signals corresponding to different independent variable sizes according to the first scanning instruction; The quantum analyzer is used to collect and perform frequency domain analysis on the signal output by the control signal monitoring unit during the period when the first waveform generating component executes the first scanning instruction, and output the frequency domain information obtained by the analysis to the host computer.

2. The measurement and control system according to claim 1, wherein: The host computer is specifically used to generate a heat map based on the frequency domain information obtained by the quantum analyzer; and determine the first optimal parameter of the sideband suppression of the first waveform generating component based on the heat map.

3. The measurement and control system according to claim 2, characterized in that: The independent variables include: one or more of relative amplitude, phase and offset; The host computer is further configured to use the spectrum amplitude of the quantum analyzer signal as a dependent variable corresponding to the independent variable, draw a heat map, identify points that meet the principles of the highest control signal amplitude, the lowest local oscillator leakage amplitude, and the lowest image frequency signal amplitude, and determine the first optimal parameter based on one or more of the relative amplitude, phase, and offset of the identified points.

4. The measurement and control system according to claim 1, wherein: The quantum analyzer is specifically used to collect the signal output by the control signal monitoring unit during the execution of the scanning instruction by the first waveform generating component, perform Fourier transform on the signal to obtain the corresponding frequency domain signal, obtain the frequency domain information of the frequency domain signal, and output it to the host computer.

5. The measurement and control system according to claim 1, wherein: The measurement and control system further comprises: a read-in signal generating unit and a read-in signal monitoring unit; The read-in signal generating unit is used to generate a read-in signal to a quantum processing unit of a quantum computer to read the state of a quantum bit in the quantum processing unit; the read-in signal generating unit includes: a second waveform generating component and a second IQ mixing component; the second waveform generating component is used to transmit a baseband signal of the read-in signal to the second IQ mixing component; The read-in signal monitoring unit is used to couple out a portion of the read-in signal generated by the read-in signal generating unit, output it to the quantum analyzer after demodulation, and output the remaining read-in signal to the quantum processing unit; The host computer is also connected to the second waveform generating component; The host computer is further configured to send a second scanning instruction to the second waveform generating component; and determine a second optimal parameter for sideband suppression of the second waveform generating component based on the frequency domain information obtained by the quantum analyzer; and return the second optimal parameter to the second waveform generating component, so that the second waveform generating component can transmit a baseband signal corresponding to the second optimal parameter, and correct the deviation of the second IQ mixing component; The second waveform generating component is configured to sequentially transmit baseband signals corresponding to different independent variable sizes according to the second scanning instruction; The quantum analyzer is used to collect and perform frequency domain analysis on the signal output by the input signal monitoring unit during the execution of the second scanning instruction by the second waveform generating component, and output the frequency domain information obtained by the analysis to the host computer.

6. The measurement and control system according to claim 5, characterized in that: The host computer is specifically used to generate a heat map based on the frequency domain information obtained by the quantum analyzer; and determine the second optimal parameter of the sideband suppression of the second waveform generating component based on the heat map.

7. The measurement and control system according to claim 6, characterized in that: The independent variables include: one or more of relative amplitude, phase and offset; The host computer is further configured to use the spectrum amplitude of the signal collected by the quantum analyzer as a dependent variable corresponding to the independent variable, draw a heat map, identify points that meet the principles of the highest amplitude of the read signal, the lowest amplitude of the local oscillator leakage, and the lowest amplitude of the image frequency signal, and determine the second optimal parameter based on one or more of the relative amplitude, phase, and offset of the identified points.

8. The measurement and control system according to claim 5, wherein: The quantum analyzer is specifically used to collect the signal output by the read-in signal monitoring unit during the execution of the scanning instruction by the second waveform generating component, perform Fourier transform on the signal to obtain the corresponding frequency domain signal, obtain the frequency domain information of the frequency domain signal, and output it to the host computer.

9. A quantum computer, characterized in that include: The measurement and control system and quantum processing unit of a quantum computer according to any one of claims 1 to 8; The control signal monitoring unit in the measurement and control system is connected to the quantum processing unit, and is used to couple out a portion of the control signal emitted by the control signal generating unit in the measurement and control system, demodulate and output it to the quantum analyzer for collection and analysis, and output the remaining control signal to the quantum processing unit for controlling the quantum bit.

10. A method for calibrating an IQ mixing component in a measurement and control system of a quantum computer according to any one of claims 1 to 8, characterized in that: include: The host computer sends a first scanning instruction to the first waveform generating component in the control signal generating unit; The first waveform generating component sequentially transmits IQ signals corresponding to different independent variable sizes according to the first scanning instruction; The quantum analyzer collects the signal output by the control signal monitoring unit during the execution of the first scanning instruction by the first waveform generating component and performs frequency domain analysis, and outputs the frequency domain information obtained by the analysis to the host computer; The host computer determines the first optimal parameter for sideband suppression of the first waveform generating component based on the frequency domain information obtained by the quantum analyzer; and returns the first optimal parameter to the first waveform generating component, so that the first waveform generating component can transmit a baseband signal corresponding to the first optimal parameter and correct the deviation of the first IQ mixing component.

11. The method according to claim 10, wherein Also includes: The host computer sends a second scanning instruction to the second waveform generating component in the read-in signal generating unit; The second waveform generating component sequentially transmits IQ signals corresponding to different independent variables according to the second scanning instruction; The quantum analyzer collects the signal output by the control signal monitoring unit during the execution of the second scanning instruction by the first waveform generating component and performs frequency domain analysis, and outputs the frequency domain information obtained by the analysis to the host computer; The host computer determines the second optimal parameters for sideband suppression of the second waveform generating component based on the frequency domain information obtained by the quantum analyzer; and returns the second optimal parameters to the second waveform generating component, so that the second waveform generating component can transmit a baseband signal corresponding to the second optimal parameters and correct the deviation of the second IQ mixing component.

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