A method and system for self-testing a quantum computer

Abstract

The application discloses a self-checking method and system of a quantum computer, and the method comprises the following steps: monitoring pulse signals in the quantum computer; measuring different pulse signals in a preset sequence and superimposing the pulse signals to obtain an actual waveform collected by self-checking; comparing the actual waveform with a calibration waveform obtained in advance to obtain a final test waveform; and analyzing a voltage value of the test waveform to quickly find whether the pulse signals have errors and locate a device where the errors occur. The application monitors all the pulse signals in the quantum computer, measures the pulse signals in a time domain, compares the pulse waveforms collected after processing with the calibration waveform, and thus realizes the self-checking function. The embodiment of the application performs different switch sequences in different time periods, sequentially displays all the pulse signals, and thus achieves the effect of quickly finding problems and quickly locating the problems.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of quantum computers, and more particularly relates to a self-checking method and system for a quantum computer. BACKGROUND

[0002] In neutral atom quantum computing, a variety of wavelengths of laser pulses are needed to manipulate quantum bits, and these microsecond-level or sub-microsecond pulses are generally generated by pulse modulation of an acousto-optic modulator, and a mechanical shutter is also needed to ensure complete turning off of the laser to avoid the influence of residual light. In addition, a plurality of directional magnetic fields are needed for atomic cooling, internal state preparation, etc., and the switching of the magnetic field is realized by current switching, and the size is controlled by the current intensity. When manipulating the internal state of the quantum bit, a microwave pulse is used, which is generated by a microwave source and a microwave horn. As can be seen, in the quantum computing system, a large number of laser short pulses, magnetic field pulses, microwave pulses, etc. are used, and the switching time and amplitude of these pulse signals directly affect the manipulation result of the quantum bit, and any error cannot occur.

[0003] However, this series of pulse signals are generated by a plurality of electronic devices, and if any of the devices has a problem, the actual pulse will not match the set pulse, thereby making the subsequent calculation result unreliable. Moreover, since the effects of the pulses are mutually influenced, it is difficult to quickly locate the electronic device that has a problem through the calculation result. Therefore, this brings two problems: 1. It is difficult to determine whether an electronic device has a fault in the timing calculation process, resulting in a mismatch between the actual pulse and the set pulse; 2. Even if the calculation result is used to deduce that the pulse has a problem, it is difficult to quickly locate the specific electronic device. These two points are fatal problems for quantum computing.

[0004] In view of this, how to overcome the technical problems existing in the prior art is a difficult problem to be solved in the technical field. SUMMARY

[0005] One of the purposes of the present application is to overcome the technical problems existing in the prior art, in order to solve the problems of difficulty in judging faults and difficulty in locating specific fault devices in existing quantum computing, a self-checking method and system for a quantum computer are provided, by using the method and system, the pulse generating devices involved in the entire computer can be checked before each calculation, and by comparing with the "calibration waveform", the electronic device that has a problem can be quickly located, thereby greatly improving the execution efficiency of the quantum computer.

[0006] To achieve the above purpose, according to the first aspect of the present application, a self-checking method for a quantum computer is provided, comprising:

[0007] Monitoring pulse signals in a quantum computer;

[0008] Measuring and superimposing different pulse signals in a preset sequence to obtain an actual waveform collected by self-checking;

[0009] Comparing the actual waveform with a calibration waveform obtained in advance to obtain a final test waveform;

[0010] By analyzing the voltage value of the test waveform, it can be quickly found out whether the pulse signal has an error and the device where the error occurs is located.

[0011] In an optional embodiment, the monitoring of the pulse signals in the quantum computer specifically includes:

[0012] Monitoring the laser pulse signal by a photodetector;

[0013] Monitoring the three-dimensional magnetic field pulse signal by a magnetometer;

[0014] Monitoring the microwave pulse signal by a microwave power meter.

[0015] In an optional embodiment, the monitoring of the laser pulse signal by the photodetector specifically includes: adding a beam splitter before the fiber coupling frame, so that a part of the modulated laser enters another fiber coupling frame, and the part of the laser is guided to a photodetector, and the voltage waveform change on the photodetector reflects the laser pulse signal on the way; guiding all laser pulse signals in the system to the same photodetector, so that the output voltage of the photodetector contains the information of the multi-channel laser pulse signal, and at the same time, all laser pulse signals are monitored;

[0016] The monitoring of the three-dimensional magnetic field pulse signal by the magnetometer specifically includes: adding a magnetometer around the magnetic field coil to monitor the change of the three-dimensional magnetic field in the system in real time;

[0017] The monitoring of the microwave pulse signal by the microwave power meter specifically includes: adding a microwave power meter near the quantum bit computing area to monitor the microwave pulse signal in the system in real time, so as to realize the monitoring of the microwave pulse signal.

[0018] In an optional embodiment, the measuring and superimposing of different pulse signals in a preset sequence to obtain an actual waveform collected by self-checking specifically includes:

[0019] Controlling each device in the system to be switched in a preset sequence by the preset sequence, so as to generate pulse signals in the preset sequence;

[0020] The output signals of the photoelectric detector, the magnetometer and the microwave power meter are collected after being switched in the preset order, to obtain voltage variation waveforms on each channel, to respectively reflect laser pulse waveforms, magnetic field switching waveforms and microwave pulse waveforms.

[0021] The voltage values of each channel are added to obtain an actual waveform collected by the self-checking.

[0022] In an optional embodiment, the pre-obtained calibration waveform is a waveform obtained by running a self-checking program when each device is normally working; and the comparing the actual waveform with the pre-obtained calibration waveform to obtain a final checking waveform specifically comprises: subtracting the actual waveform from the calibration waveform by the self-checking program to obtain the final checking waveform.

[0023] In an optional embodiment, the quickly finding whether the pulse signal is wrong and locating the device where the error occurs by analyzing the voltage value of the checking waveform specifically comprises:

[0024] If the voltage value of the checking waveform is 0 throughout the whole time sequence, the voltage values of the actual waveform and the calibration waveform are the same throughout the whole time sequence, proving that the working conditions of all devices are normal and no device error response occurs.

[0025] If the voltage value of the checking waveform is not 0 in a certain time period, the actual waveform and the calibration waveform deviate, and the time period where the error occurs is located and the preset order is combined to quickly locate the device where the error occurs.

[0026] In the second aspect, the application provides a self-checking system of a quantum computer, which applies the self-checking method of the quantum computer as described in the first aspect, and comprises a host, an acquisition card, a quantum bit computing area, a microwave control module, a magnetic field current source module, a photoelectric detector and a plurality of laser modules; wherein:

[0027] The quantum bit computing area comprises a laser input port connected with the plurality of laser modules, a microwave input port connected with the microwave control module, a current input port connected with the magnetic field current source module, a microwave power meter for measuring a microwave pulse, and a magnetic field meter for measuring a magnetic field waveform;

[0028] The photoelectric detector is connected with the plurality of laser modules for laser pulse measurement;

[0029] The acquisition card is connected with the photoelectric detector, the microwave power meter and the magnetic field meter on one hand, and connected with the host on the other hand, for collecting laser pulse signals, microwave pulse signals and magnetic field pulse signals and transmitting them to the host.

[0030] In an alternative embodiment, each of the laser modules comprises a laser, a modulator, a mechanical shutter, a beam splitter, a first fiber coupler, a second fiber coupler, a modulator driving device, and a mechanical shutter driving device, wherein:

[0031] The laser output by the laser is modulated by the modulator and the mechanical shutter; the modulation signal output by the modulator driving device is transmitted to the input end of the modulator through electrical connection to realize frequency and pulse modulation of the laser; the control signal output by the mechanical shutter driving device is transmitted to the input end of the mechanical shutter through electrical connection to realize fast-off action of the laser; the laser beam is split into two beams by the beam splitter, one of which is a high-power laser coupled into the first fiber coupler for input into the quantum bit calculation area to realize manipulation of the quantum bit; the other is a low-power laser coupled into the second fiber coupler and transmitted through the optical fiber to be incident on the photodetector.

[0032] In an alternative embodiment, the microwave manipulation module comprises a microwave source, a microwave switch, and a microwave power amplifier, wherein:

[0033] The microwave signal output by the microwave source is transmitted to the microwave switch through electrical connection, and the microwave switch is used to realize switching of the microwave signal to realize microwave pulse modulation function; the signal passing through the microwave switch is connected to the microwave power amplifier through a cable to realize amplification of the microwave signal; the amplified microwave signal is transmitted to the microwave input port of the quantum bit calculation area through electrical connection to realize microwave manipulation of the quantum bit.

[0034] In an alternative embodiment, the magnetic field current source module comprises a plurality of current sources for supplying power to the magnetic field coil, and the current signal output by the current source is input to the current input port of the quantum bit calculation area through electrical connection to supply power to the magnetic field coil.

[0035] Overall, compared with the prior art, the above technical solutions conceived by the present application have the following beneficial effects: all pulse signals in the quantum computer are monitored and measured in the time domain, and by comparing the processed pulse waveform with the "calibration waveform", a self-checking function is realized. The present embodiment performs different switching sequences at different time periods, sequentially displays all pulse signals, and achieves the effect of quickly finding and positioning problems. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 A self-checking method flowchart of a quantum computer according to Embodiment 1 of the present application;

[0037] Figure 2The step 100 extension flow chart provided for the embodiment 1 of the present application;

[0038] Figure 3 The step 200 extension flow chart provided for the embodiment 1 of the present application;

[0039] Figure 4 The waveform schematic diagram provided for the embodiment 1 of the present application;

[0040] Figure 5 The module structure block diagram of the self-checking system of a quantum computer provided for the embodiment 2 of the present application;

[0041] Figure 6 The structure schematic diagram of the self-checking device of a quantum computer provided for the embodiment 4 of the present application. DETAILED DESCRIPTION

[0042] The present application will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application. These are all within the scope of protection of the present application.

[0043] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0044] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict, and are all within the scope of protection of the present application. In addition, although the functional modules are divided in the device schematic diagram, and the logical order is shown in the flow chart, in some cases, the steps shown or described can be different from the module division in the device or the order of execution in the flow chart.

[0045] Unless otherwise defined, all technical and scientific terms used in the specification have the same meaning as commonly understood by those skilled in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as there is no conflict.

[0046] In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as there is no conflict.

[0047] The present application will be described in detail below with reference to the drawings and embodiments.

[0048] Embodiment 1:

[0049] As Figure 1 shown, the present application provides a self-checking method of a quantum computer, comprising the following steps.

[0050] Step 100: monitoring the pulse signals in the quantum computer. In this step of the embodiment, the signals involved in the quantum computer include laser pulses, magnetic field switching signals (magnetic field pulses), microwave pulses, special modulation pulses, etc. The embodiment focuses on laser pulses, magnetic field pulses and microwave pulses. It should be noted that the special modulation pulse is a special case of the laser pulse; generally, the laser pulse is in the form of a square wave, and in special cases it may have a special waveform, which is not a simple square wave; however, the inspection method is the same as that of the square wave pulse, and the same is compared with the standard after being collected; the special modulation pulse can be classified as a laser pulse.

[0051] Step 200: measuring and superimposing different pulse signals through a preset sequence to obtain the actual waveform collected by self-checking. In this step of the embodiment, a specific sequence of pulse sequences can be set by the host to control the modulator driving device, mechanical shutter driving device, microwave switch, magnetic field current source, etc. in the system, so that these devices are switched in a specific sequence, thereby generating a specific sequence of pulse signals, and then superimposing each pulse signal to obtain the actual waveform.

[0052] Step 300: comparing the actual waveform with the pre-obtained calibration waveform to obtain the final inspection waveform. In this step of the embodiment, through the preparation in advance, the error-free "calibration waveform" can be obtained, and by subtracting the actual waveform from the calibration waveform, the final inspection waveform can be obtained.

[0053] Step 400: analyzing the voltage value of the inspection waveform to quickly find out whether the pulse signal has an error and locate the device where the error occurs. In this step of the embodiment, if the inspection waveform maintains a voltage value of 0 throughout the time sequence, it means that there is no error and all devices are working properly. If the voltage value of the inspection waveform is not 0 in a certain time period, it means that there is an error, and through the time period and the preset time sequence, the device where the error occurs can be located.

[0054] Through the above steps, all pulse signals in the quantum computer are monitored and measured in the time domain, and the collected pulse waveform is compared with the "calibration waveform" after processing, thereby realizing the self-checking function. The embodiment of the present application executes different switching sequences in different time periods, sequentially displays all pulse signals, and achieves the effect of quickly finding out and quickly locating the problem.

[0055] Reference Figure 2 As shown in the specific implementation of the preferred embodiment, the monitoring of the pulse signals in the quantum computer in step 100 specifically includes the following steps:

[0056] Step 101: Monitor the laser pulse signals through a photodetector. In this step of the embodiment, a beamsplitter can be added before the fiber coupler to allow a small portion of the modulated laser to enter another fiber coupler and be guided to a photodetector, and the voltage waveform change on the photodetector can reflect how the laser pulse signals work. All the laser pulse signals in the system are guided to the same photodetector, so that the output voltage of the photodetector contains the information of the multiple laser pulse signals, and all the laser pulse signals are monitored at the same time.

[0057] Step 102: Monitor the three-dimensional magnetic field pulse signals through a magnetometer. In this step of the embodiment, a magnetometer can be added around the magnetic field coil to monitor the changes of the three-dimensional magnetic field in the system in real time.

[0058] Step 103: Monitor the microwave pulse signals through a microwave power meter. In this step of the embodiment, a microwave power meter can be added near the qubit computing area to monitor the microwave pulse signals in the system in real time, so as to monitor the microwave pulse signals.

[0059] It should be noted that to implement the above method, a complete monitoring system needs to be established first. The signals involved in the quantum computer include laser pulses, magnetic field switching signals, microwave pulses, and special modulation pulses. The laser pulses are generated by an acousto-optic modulator, an electro-optic modulator, or an optical fiber modulator, and the switching of the laser is realized through an external control signal. The width of the laser pulse is usually between tens of nanometers and tens of milliseconds. After the laser is turned off by the modulator, there is always very weak light leakage, so a mechanical switch is needed to completely turn off the laser, and the speed of the mechanical switch is usually in the order of milliseconds. In the embodiment of the present application, a beamsplitter (for example, a 5% beamsplitter) is added before the fiber coupler (for example, fiber coupler 1-1 in FIG. 1) that enters the computing system, so that a small portion of the laser modulated by the modulator enters another fiber coupler (for example, fiber coupler 1-2 in FIG. 1), and this portion of the laser is guided to a photodetector. In this way, the voltage waveform change on the photodetector can reflect how the laser pulse signals work. All the laser pulse signals in the system are guided to the same photodetector (which can also be multiple photodetectors), and the output voltage of the photodetector contains the information of the multiple laser pulses, and all the laser pulses are monitored at the same time. Figure 5 Figure 5 It should be noted that to implement the above method, a complete monitoring system needs to be established first. The signals involved in the quantum computer include laser pulses, magnetic field switching signals, microwave pulses, and special modulation pulses. The laser pulses are generated by an acousto-optic modulator, an electro-optic modulator, or an optical fiber modulator, and the switching of the laser is realized through an external control signal. The width of the laser pulse is usually between tens of nanometers and tens of milliseconds. After the laser is turned off by the modulator, there is always very weak light leakage, so a mechanical switch is needed to completely turn off the laser, and the speed of the mechanical switch is usually in the order of milliseconds. In the embodiment of the present application, a beamsplitter (for example, a 5% beamsplitter) is added before the fiber coupler (for example, fiber coupler 1-1 in FIG. 1) that enters the computing system, so that a small portion of the laser modulated by the modulator enters another fiber coupler (for example, fiber coupler 1-2 in FIG. 1), and this portion of the laser is guided to a photodetector. In this way, the voltage waveform change on the photodetector can reflect how the laser pulse signals work. All the laser pulse signals in the system are guided to the same photodetector (which can also be multiple photodetectors), and the output voltage of the photodetector contains the information of the multiple laser pulses, and all the laser pulses are monitored at the same time.​

[0060] The magnetic field in quantum computing is a very important parameter, and the magnetic field cannot be separated when the quantum bits are trapped and manipulated. Usually, different directions and sizes of magnetic field are generated by adding different currents to the Helmholtz coil or the anti-Helmholtz coil, and the control of the magnetic field can be realized by controlling the size and switch of the current. The current is generated by an externally controllable current source. By adding a magnetometer around the magnetic field coil (which is also near the quantum bit computing area), the changes of the three-dimensional magnetic field in the system can be monitored in real time. Similarly, a microwave power meter can be added near the quantum bit computing area to monitor the microwave pulse signal in the system in real time, thereby monitoring the microwave pulse signal. The output signals of the above-mentioned photodetector, magnetometer and microwave power meter are all collected by the acquisition card and transmitted to the host computer, thereby completing the monitoring of all change signals in the system.

[0061] Reference Figure 3 In one specific embodiment of the preferred embodiment, the step 200 of measuring and superimposing different pulse signals in a preset order to obtain the actual waveform collected by self-checking specifically includes the following steps:

[0062] Step 201: Control each device in the system to switch in a preset order through a preset order, thereby generating a pulse signal in a preset order. In this step of the embodiment, a specific order of pulse sequence is set by the host computer to control the modulator driving device, mechanical shutter driving device, microwave switch, magnetic field current source, etc. in the system, so that these devices are switched in a specific order, thereby generating a pulse signal in a specific order. For example, the self-checking program controls the modulator switch and shutter switch of the laser 1, the modulator switch and shutter switch of the laser 2, the modulator switch and shutter switch of the laser N, the switch of the magnetic field 1, the switch of the magnetic field 2, the switch of the magnetic field N, the switch of the microwave, etc. in different time periods. Then the lasers 1, 2, 3 and N will be switched in turn, followed by the switching of the magnetic field, and then the switching of the microwave, and the pulse signal will also be generated in this order.

[0063] Step 202: After the photodetector output signal, the magnetometer output signal and the microwave power meter output signal are switched in a preset order, the voltage change waveform on each channel is obtained to reflect the laser pulse waveform, the magnetic field switching waveform and the microwave pulse waveform respectively. In this step of the embodiment, on the basis of step 201, all monitoring signals are collected by the acquisition card and the voltage change waveform on each channel is obtained on the computer program, such as the laser pulse waveform on channel 1, the magnetic field switching waveform on channel 2, and the microwave pulse waveform on channel 3.

[0064] Step 203: add the voltage values of each channel to obtain the actual waveform collected in this self-test. In this step of the embodiment, on the basis of step 202, adding the voltage values of each channel can obtain the actual waveform W1 collected in this self-test, as shown in Figure 4

[0065] In one specific implementation of the preferred embodiment, the comparison of the actual waveform with the pre-obtained calibration waveform in step 300 to obtain the final test waveform specifically includes: subtracting the obtained actual waveform from the calibration waveform through the self-test program to obtain the final test waveform. The pre-obtained calibration waveform is the waveform obtained by running the self-test program when each device is working normally; through the previous preparation, we can pre-obtain the error-free calibration waveform W0, that is, the waveform obtained by running the self-test program when each device is working normally is the calibration waveform. This can be ensured by the previous error correction and inspection that each device is working normally, and then the calibration waveform W0 is obtained, as shown in Figure 4 The calibration waveform is a standard waveform of a system, and it does not need to be updated when the system does not increase or decrease devices, so the calibration waveform can be used for a long time once obtained.

[0066] In one specific implementation of the preferred embodiment, the analysis of the voltage value of the test waveform in step 400 to quickly find out whether the pulse signal has an error and locate the device where the error occurs specifically includes: if the test waveform maintains a voltage value of 0 throughout the entire time sequence, it means that the voltage values of the actual waveform and the calibration waveform are the same throughout the entire time sequence, proving that the working conditions of all devices are normal and no device error response occurs; if the voltage value of the test waveform is not 0 in a certain time period, it means that the actual waveform and the calibration waveform have deviations, and the device where the error occurs can be quickly located by locating the time period where the error occurs and combining the preset sequence. Specifically, subtracting the obtained actual waveform W1 from the calibration waveform W0 through the self-test program can obtain the final test waveform W2, as shown in Figure 4 Figure 4 ​​As shown, for example, the first time period of the W2 waveform appears a downward square waveform, which indicates that the power of the laser 1 is reduced, but the switching function of the modulator is normal, at this time, the power of the laser and the intensity of the modulator signal need to be checked. For example, the fourth time of the W2 waveform appears a waveform completely opposite to the calibration waveform, which indicates that the mechanical switch of the laser 2 is not normally opened and is in the closed state, at this time, it is necessary to check whether the mechanical switch has a problem. For the voltage signals in other time periods, the same numerical analysis can be done to determine whether the magnetic field switch is normal, whether the microwave pulse is normal, and so on.

[0067] In summary, the present application provides a self-checking method of a quantum computer, which monitors all pulse signals in the quantum computer and measures in the time domain, compares the processed pulse waveform with the calibration waveform, and thus realizes the self-checking function.

[0068] Embodiment 2:

[0069] The embodiment of the present application also provides a self-checking system of a quantum computer, which applies the self-checking method of the quantum computer provided in the above embodiment, refers to Figure 5 As shown, a module structure block diagram of a self-checking system of a quantum computer provided in the embodiment. The system of the embodiment includes a host computer, an acquisition card, a quantum bit computing area, a microwave control module, a magnetic field current source module, a photoelectric detector, and a plurality of laser modules, the plurality of laser modules are respectively represented as laser module 1, laser module 2,..., and laser module N in Figure 5 The quantum bit computing area contains a laser input port connected with the plurality of laser modules, a microwave input port connected with the microwave control module, a current input port connected with the magnetic field current source module, a microwave power meter for microwave pulse measurement, and a magnetic field meter for magnetic field waveform measurement; the photoelectric detector is connected with the plurality of laser modules for laser pulse measurement; the acquisition card is connected with the photoelectric detector, the microwave power meter, and the magnetic field meter on one hand, and connected with the host computer on the other hand, for acquiring laser pulse signals, microwave pulse signals, and magnetic field pulse signals and transmitting to the host computer.

[0070] In the embodiment, each of the laser modules comprises a laser, a modulator, a mechanical shutter, a light splitting plate, a first fiber coupler, a second fiber coupler, a modulator driving device and a mechanical shutter driving device. The laser output laser light which is modulated by the modulator and then passes through the mechanical shutter. The modulator driving device outputs a modulation signal which is transmitted to the input end of the modulator by electrical connection to realize frequency and pulse modulation of the laser light. The mechanical shutter driving device outputs a control signal which is transmitted to the input end of the mechanical shutter by electrical connection to realize fast-off function of the laser light. Then the laser beam is split into two beams by the light splitting plate, one of which is high-power laser light coupled into the first fiber coupler for input into the quantum bit calculation area to realize manipulation of the quantum bit, and the other is low-power laser light coupled into the second fiber coupler and then transmitted by the optical fiber to be incident on the photodetector.

[0071] For example Figure 5 In the embodiment, each of the laser modules comprises a laser, a modulator, a mechanical shutter, a light splitting plate, a first fiber coupler, a second fiber coupler, a modulator driving device and a mechanical shutter driving device. The laser output laser light which is modulated by the modulator and then passes through the mechanical shutter. The modulator driving device outputs a modulation signal which is transmitted to the input end of the modulator by electrical connection to realize frequency and pulse modulation of the laser light. The mechanical shutter driving device outputs a control signal which is transmitted to the input end of the mechanical shutter by electrical connection to realize fast-off function of the laser light. Then the laser beam is split into two beams by the light splitting plate, one of which is high-power laser light coupled into the first fiber coupler for input into the quantum bit calculation area to realize manipulation of the quantum bit, and the other is low-power laser light coupled into the second fiber coupler and then transmitted by the optical fiber to be incident on the photodetector.

[0072] In the embodiment, the microwave manipulation module comprises a microwave source, a microwave switch and a microwave power amplifier. The microwave source outputs a microwave signal which is transmitted to the microwave switch by electrical connection. The microwave switch is used to realize switching of the microwave signal to realize microwave pulse modulation function. The signal passing through the microwave switch is connected to the microwave power amplifier by a cable to realize amplification of the microwave signal. The amplified microwave signal is transmitted to the microwave input port of the quantum bit calculation area by electrical connection to realize microwave manipulation of the quantum bit.

[0073] In the embodiment, the magnetic field current source module comprises a plurality of current sources for supplying power to the magnetic field coils, for example Figure 5The current sources of the magnetic field coil 1, the magnetic field coil 2,..., and the magnetic field coil N are electrically connected to the current input port of the quantum bit calculation area, and are used to supply power to the magnetic field coil.

[0074] In the quantum bit calculation area, the microwave power meter receives the microwave signal from the microwave input port, converts it into a voltage signal, and then transmits it to the input end of the acquisition card through electrical connection. The magnetic field meter can measure the size of the three-dimensional magnetic field in the system, convert it into a voltage signal, and then transmit it to the input end of the acquisition card through electrical connection. The acquisition card transmits all the signals collected by multiple channels to the computer host through a cable after processing.

[0075] Through the above system setting, the embodiment monitors all pulse signals in the quantum computer, and when self-checking of the quantum computer is needed, the method in embodiment 1 is used to measure in the time domain, and the collected pulse waveform is compared with the calibration waveform after processing, so as to realize the self-checking function.

[0076] In summary, the present application provides a self-checking system for a quantum computer, which can quickly check whether each controller of the quantum computer has a problem by running the self-checking system after each startup. Different switch sequences are executed in different time periods, and all pulse signals are sequentially displayed, so that the problem can be quickly found and located.

[0077] Embodiment 3:

[0078] Based on the description of the self-checking method and system of the quantum computer in the above embodiments, the embodiment further provides a method for detecting the magnetic field to improve the accuracy of the magnetic field strength measurement.

[0079] It should be noted that in the embodiments 1 and 2, the actual waveforms collected by self-checking the pulse signals are compared with the calibration waveforms, so that the electronic equipment with problems can be quickly located. The actual waveforms are obtained by measuring and superimposing different pulse signals, including laser pulse signals, three-dimensional magnetic field pulse signals and microwave pulse signals. For the three-dimensional magnetic field pulse signals, measurement is a difficulty in the prior art, and measurement errors often occur. When the method of the embodiments 1 and 2 is used for fault detection, because the actual waveforms and the calibration waveforms are measured by using a set of measurement methods, even if there are measurement errors, in most cases, comparison between the two can obtain relatively accurate self-checking results. However, in some coincidental cases, when there is a problem in some equipment, because of the existence of measurement errors, the actual waveforms after superimposing the measurement errors cannot be compared with the calibration waveforms to find the problem, resulting in misjudgment. Or when there is no problem in the equipment, because of the existence of measurement errors, the actual waveforms after superimposing the measurement errors are compared with the calibration waveforms to find the problem, resulting in misjudgment. Based on the two special coincidental cases, the measurement of the three-dimensional magnetic field pulse signals is optimized in this embodiment, so that the measurement accuracy is improved, the error is reduced, and the possibility of misjudgment is reduced.

[0080] It should be noted that the magnetic field used by the quantum computer is three-dimensional orthogonal, and has corresponding components in x, y and z directions. The fluxgate meter (magnetometer) commonly used to measure the magnetic field can measure the three-dimensional orthogonal magnetic field, and can measure the magnetic field strength in three directions. However, the fluxgate meter cannot be placed at the center of the system magnetic field (the center of the system magnetic field is the experimental area, and other equipment cannot be placed), but only can be placed far from the center, so the magnetic field measured by the fluxgate meter is not the most real magnetic field size at the center of the system, but has a certain deviation. In order to more accurately reflect the change of the system magnetic field strength, the three measurement axes of the fluxgate meter should coincide with the three axes of the three-dimensional orthogonal magnetic field of the system as much as possible. In this way, each measurement axis can independently measure the magnetic field in each direction, avoiding the influence of the measurement of the x-axis direction on the measurement of the y-axis direction. (Because if the measurement axes do not coincide, the magnetic field in the x-axis direction will have a projection component in the other two axes of the fluxgate meter, thereby affecting the measurement of the other two axes.)

[0081] The following specifically introduces how to align the three measurement axes of the fluxgate meter with the three orthogonal magnetic field axes of the system, that is, the three-dimensional magnetic field pulse signal optimization measurement method adopted in the embodiment. ①First, determine the directions of the three orthogonal magnetic fields of the system, which are denoted as x direction, y direction and z direction respectively. ②Place the fluxgate meter as close to the center of the system magnetic field as possible, and adjust the direction of the fluxgate meter by visual observation to make the three measurement axes align with the three orthogonal magnetic field directions of the system as much as possible. ③Open the magnetic field in a certain direction of the system alone, for example, open the magnetic field in the x direction. Then measure by the fluxgate to obtain the magnetic field data in three directions, which are denoted as x1, y1 and z1 respectively. ④Rotate the direction of the fluxgate meter to make the measurement values of y1 and z1 minimum; and when we adjust the size of the magnetic field in the x direction of the system, only the measurement value of x1 changes, and y1 and z1 do not change. At this time, it is indicated that the x axis of the fluxgate meter has been aligned with the x axis of the system magnetic field. ⑤Open the magnetic field in the y direction, align steps ③ and ④, until the y axis of the fluxgate meter is aligned with the y axis of the system magnetic field. ⑥Open the magnetic field in the z direction, align steps ③ and ④, until the z axis of the fluxgate meter is aligned with the z axis of the system magnetic field. At this time, the three-axis directions of the fluxgate meter are aligned with the three-axis directions of the system magnetic field.

[0082] The three-dimensional magnetic field pulse signal measured by the above method has improved accuracy, which can reduce errors and further reduce the possibility of misjudgment.

[0083] Embodiment 4:

[0084] On the basis of the self-checking method of the quantum computer provided in the above embodiment, the application further provides a self-checking device of a quantum computer which can be used to implement the above method, as shown in Figure 6 The device architecture schematic diagram of the embodiment of the application is shown. The self-checking device of the quantum computer of the embodiment comprises one or more processors 21 and a memory 22. Among them, Figure 6 The processor 21 is taken as an example in the embodiment.

[0085] The processor 21 and the memory 22 can be connected through a bus or other means, Figure 6 The connection through the bus is taken as an example.

[0086] The memory 22 is a non-volatile computer readable storage medium, which can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as the self-checking method of the quantum computer in the embodiment 2. The processor 21 executes the various functions and data processing of the self-checking device of the quantum computer by running the non-volatile software programs, instructions and modules stored in the memory 22, that is, implements the self-checking method of the quantum computer of the embodiment of the application.

[0087] Memory 22 can include high-speed random access memory, and can also include nonvolatile memory, such as at least one magnetic disk storage device, flash memory device, or other nonvolatile solid-state storage device. In some embodiments, memory 22 can optionally include memory that is remotely located from processor 21, such as in a "cloud" or other network storage, which can be connected to processor 21 via a network. Examples of such networks include, but are not limited to, the Internet, intranet, local area network, mobile communications network, and combinations thereof.

[0088] Program instructions / modules are stored in memory 22, which when executed by one or more processors 21, perform the self-test method of a quantum computer in the embodiments described above, such as the self-test method described above in connection with Figure 1 each of the steps illustrated.

[0089] Those of ordinary skill in the art will appreciate that all or portions of the steps in the various methods of the embodiments can be implemented by program instructions. Such program instructions can be utilized to direct an associated processor or other processing device to implement aspects of the methods. Program instructions stored on a computer- readable storage medium can direct a processor or other associated processing device to execute techniques disclosed herein. Program instructions implemented by one or more processors 21 to perform the steps of the methods described above can be stored on a computer- readable storage medium such as memory 22.

[0090] The above description is only preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application. The contents not described in detail in the specification belong to the prior art known by those skilled in the art.

Claims

1. A method of self-testing a quantum computer, the method comprising: The application relates to a self-checking method for pulse signals in a quantum computer. The method comprises the following steps: monitoring the pulse signals in the quantum computer; measuring and superimposing different pulse signals in a preset sequence to obtain an actual waveform collected by self-checking; comparing the actual waveform with a calibration waveform obtained in advance to obtain a final test waveform; analyzing voltage values of the test waveform to quickly find whether the pulse signals have errors and locate the device where the error occurs; the monitoring of the pulse signals in the quantum computer specifically comprises the following steps: monitoring laser pulse signals by means of a photodetector, monitoring three-dimensional magnetic field pulse signals by means of a magnetometer and monitoring microwave pulse signals by means of a microwave power meter; the monitoring of the laser pulse signals by means of the photodetector specifically comprises the following steps: adding a light splitting piece before a fiber coupling frame to make a part of the modulated laser enter another fiber coupling frame and guide the part of the laser to a photodetector, and reflecting the laser pulse signals on the way by means of voltage waveform changes on the photodetector; guiding all the laser pulse signals in the system to the same photodetector so that the output voltage of the photodetector contains information of the multiple laser pulse signals and simultaneously monitors all the laser pulse signals; 2. The self-test method of a quantum computer according to claim 1, wherein, the monitoring of the three-dimensional magnetic field pulse signals by means of the magnetometer specifically comprises the following step: adding a magnetometer around a magnetic field coil to monitor the change of the three-dimensional magnetic field in the system in real time; the monitoring of the microwave pulse signals by means of the microwave power meter specifically comprises the following step: adding a microwave power meter near a quantum bit computing area to monitor the microwave pulse signals in the system in real time and realize the monitoring of the microwave pulse signals. the measurement and superimposition of the different pulse signals in the preset sequence to obtain the actual waveform collected by self-checking specifically comprises the following steps: controlling each device in the system to be switched in the preset sequence by means of the preset sequence to generate pulse signals in the preset sequence; collecting the output signals of the photodetector, the output signals of the magnetometer and the output signals of the microwave power meter after the switching of the photodetector, the magnetometer and the microwave power meter in the preset sequence to obtain voltage change waveforms on each channel to respectively reflect laser pulse waveforms, magnetic field switching waveforms and microwave pulse waveforms; 3. The method of self-testing a quantum computer according to any of claims 1-2, wherein, adding the voltage values of the channels to obtain the actual waveform collected by self-checking this time. the calibration waveform obtained in advance is a waveform obtained by running a self-checking program when each device works normally; 4. The method of self-testing a quantum computer of any of claims 1-2, wherein, the comparison of the actual waveform with the calibration waveform to obtain the final test waveform specifically comprises the following step: subtracting the actual waveform from the calibration waveform by means of the self-checking program to obtain the final test waveform. the analysis of the voltage values of the test waveform to quickly find whether the pulse signals have errors and locate the device where the error occurs specifically comprises the following steps: if the voltage value of the test waveform remains 0 in the whole time sequence, the voltage values of the actual waveform and the calibration waveform are the same in the whole time sequence, the working conditions of all the devices are normal and no device error response occurs. If the voltage value of the test waveform is not 0 in a certain time period, the actual waveform deviates from the calibration waveform, the error time period is located, and the preset sequence is combined to quickly locate the device with the error.

5. A self-checking system of a quantum computer, which applies the self-checking method of the quantum computer according to any one of claims 1 to 4, characterized in that, The device comprises a host, a collection card, a quantum bit calculation area, a microwave control module, a magnetic field current source module, a photoelectric detector, and a plurality of laser modules. The quantum bit calculation area comprises laser input ports connected to the plurality of laser modules, microwave input ports connected to the microwave control module, current input ports connected to the magnetic field current source module, a microwave power meter for microwave pulse measurement, and a magnetic field meter for magnetic field waveform measurement. The photoelectric detector is connected to the plurality of laser modules for laser pulse measurement. The collection card is connected to the photoelectric detector, the microwave power meter, and the magnetic field meter on one hand, and is connected to the host on the other hand, for collecting laser pulse signals, microwave pulse signals, and magnetic field pulse signals and transmitting them to the host.

6. The self-test system of a quantum computer according to claim 5, wherein, Each laser module comprises a laser, a modulator, a mechanical shutter, a light splitting sheet, a first fiber coupler, a second fiber coupler, a modulator driving device, and a mechanical shutter driving device. The laser output by the laser is modulated by the modulator and then passes through the mechanical shutter.

7. The self-test system of a quantum computer according to claim 5, wherein, The modulator driving device outputs a modulation signal which is transmitted to the input end of the modulator through electrical connection to realize frequency and pulse modulation of the laser. The mechanical shutter driving device outputs a control signal which is transmitted to the input end of the mechanical shutter through electrical connection to realize fast closing of the laser.

8. The self-test system of a quantum computer according to claim 5, wherein, The laser beam is split into two beams by the light splitting sheet, one of which is a high-power laser coupled into the first fiber coupler for input into the quantum bit calculation area to realize quantum bit control. The other low-power laser is coupled into the second fiber coupler and transmitted through the optical fiber to the photoelectric detector. The microwave control module comprises a microwave source, a microwave switch, and a microwave power amplifier. The microwave signal output by the microwave source is transmitted to the microwave switch through electrical connection, and the microwave switch is used to realize switching of the microwave signal to realize microwave pulse modulation function. The signal passing through the microwave switch is connected to the microwave power amplifier through a cable to realize amplification of the microwave signal. The amplified microwave signal is transmitted to the microwave input port of the quantum bit calculation area through electrical connection to realize microwave control of the quantum bit. The magnetic field current source module comprises a plurality of current sources for supplying power to the magnetic field coil. The current signal output by the plurality of current sources for supplying power to the magnetic field coil is input to the current input port of the quantum bit calculation area through electrical connection for supplying power to the magnetic field coil.

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