Quantum bit drive signal generation device, generation method, and quantum computer

Abstract

The present application discloses a device for generating a qubit drive signal, the device comprising: a microwave source module for outputting multiple microwave signals of different frequencies; a control module connected to the microwave source module for determining a phase coherence point based on the frequency or phase of two microwave signals, and outputting a trigger signal based on the phase coherence point; wherein the phase coherence point is the moment when the phase difference between the first microwave signal and the second microwave signal is consistent; a waveform output module for outputting an intermediate frequency signal corresponding to the multiple qubit drive signals in response to the trigger signal; and a signal processing module connected to the microwave source module and the waveform output module for outputting multiple qubit drive signals based on the multiple intermediate frequency signals and the multiple microwave signals. The phase coherence of the multiple qubit drive signals generated by the present application is improved.

Description

Technical Field

[0001] The present application relates to the field of quantum computing, and in particular to a device and method for generating a qubit drive signal, and a quantum computer. Background Art

[0002] Quantum chips are the core components for running quantum computing. Multiple qubits are integrated on a quantum chip. To ensure the normal operation of the qubits, a dedicated quantum measurement and control system is needed to provide various drive signals for each qubit, such as qubit drive signals that drive the quantum state information of the qubit. The qubit drive signals are generated by mixing microwave signals and intermediate frequency signals through a mixer. With technological advancements, the number of qubits on a quantum chip has increased to hundreds, or even thousands or tens of thousands. The number of qubit drive signals required has increased accordingly, as has the number of microwave sources. Furthermore, because the frequencies of the qubits are different, the frequencies of the corresponding quantum state control signals applied are different. In the prior art, when multiple microwave sources are used to output microwave signals of different frequencies to generate qubit drive signals of different frequencies, the phase difference between the microwave signals output by the multiple microwave sources changes constantly, making it difficult for the phases of the multiple qubit drive signals to be coherent. Summary of the Invention

[0003] The purpose of this application is to provide a device and method for generating a qubit drive signal, as well as a quantum computer, to address the shortcomings and deficiencies of the prior art, and to ensure that the phases of the output multi-channel qubit drive signals are coherent.

[0004] According to one aspect of the present application, there is provided a device for generating a qubit drive signal, wherein the qubit drive signal is obtained by processing an intermediate frequency signal and a microwave signal. The device comprises: a microwave source module for outputting multiple microwave signals of different frequencies, wherein the frequencies of the microwave signals correspond to the frequencies of the qubit drive signals; a control module, connected to the microwave source module, for determining a phase coherence point based on the frequencies or phases of the two microwave signals, and outputting a trigger signal based on the phase coherence point; wherein the phase coherence point is the moment when the phase difference between the two microwave signals is consistent; a waveform output module, connected to the control module, for outputting intermediate frequency signals corresponding to the multiple qubit drive signals in response to the trigger signal; and a signal processing module, connected to the microwave source module and the waveform output module, for outputting the multiple qubit drive signals based on the multiple intermediate frequency signals and the multiple microwave signals.

[0005] The device for generating a qubit drive signal as described above, further, the microwave source module includes a first microwave source and a second microwave source, wherein the frequency of a first microwave signal output by the first microwave source is lower than the frequency of a second microwave signal output by the second microwave source.

[0006] As described above, the device for generating a quantum bit drive signal, further, when the control module determines the phase coherence point based on the frequencies of the two microwave signals and outputs a trigger signal according to the phase coherence point, the control module includes: a frequency difference determination unit, used to determine the frequency difference between the two microwave signals; a trigger period determination unit, used to determine the inverse of the frequency difference as the trigger period of the phase coherence point; and a first trigger unit, used to output the trigger signal based on the trigger period.

[0007] In the qubit drive signal generating device described above, further, the first microwave signal and the second microwave signal correspond to different qubit drive signals, respectively, and the frequency difference determining unit is used to determine the frequency difference between the first microwave signal and the second microwave signal.

[0008] In the device for generating a qubit drive signal as described above, further, the first microwave signal and the second microwave signal correspond to the same qubit drive signal, and the frequency difference determination unit is used to: determine the frequency difference between two first microwave signals of different frequencies; wherein the two first microwave signals respectively correspond to qubit drive signals of different frequencies.

[0009] The device for generating a qubit drive signal as described above, further, the second microwave source is used to output two second microwave signals based on the frequency difference between the two first microwave signals; wherein the frequency difference between the two second microwave signals is an integer multiple of the frequency difference between the two first microwave signals.

[0010] The device for generating a qubit drive signal as described above, further, the first trigger unit is used to output the trigger signal at a time that is an integer multiple of the trigger period.

[0011] The device for generating a qubit drive signal as described above, further, when the control module determines a phase coherence point based on the phases of the two microwave signals and outputs a trigger signal according to the phase coherence point, the control module includes: a first phase difference determination unit, used to determine the phase difference between the first microwave signal and the second microwave signal at the same time as a preset phase difference; a first phase measurement unit, used to obtain the current phase difference between the first microwave signal and the second microwave signal; a second trigger unit, used to determine the moment when the current phase difference and the preset phase difference are the same as the phase coherence point, and output the trigger signal at the phase coherence point.

[0012] The device for generating a qubit drive signal as described above, further, when the control module determines a phase coherence point based on the phases of the two microwave signals and outputs a trigger signal according to the phase coherence point, the control module includes: a second phase difference determination unit, used to determine the difference between the first phase difference of the two first microwave signals and the second phase difference of the two second microwave signals at the same moment as a preset phase difference; a second phase measurement unit, used to obtain the current first phase difference of the two first microwave signals and the current second phase difference of the two second microwave signals; a third triggering unit, used to determine the moment when the difference between the current first phase difference and the current second phase difference is the same as the preset phase difference as the phase coherence point, and output the trigger signal at the phase coherence point.

[0013] The device for generating a qubit drive signal as described above, further, the waveform output module includes at least two waveform generators, each waveform generator is used to output at least one intermediate frequency signal in response to the trigger signal.

[0014] In the device for generating a qubit drive signal as described above, further, the control module simultaneously sends the trigger signal to each of the waveform generators.

[0015] The device for generating a qubit drive signal as described above, further, the signal processing module includes at least two mixing units, each of which is used to: output one qubit drive signal based on the two intermediate frequency signals and one first microwave signal; or output one qubit drive signal based on the two intermediate frequency signals and one second microwave signal.

[0016] As described above, the device for generating a qubit drive signal further comprises the signal processing module including at least two mixing units, each of the mixing units being configured to output a qubit drive signal based on one intermediate frequency signal, one first microwave signal, and one second microwave signal.

[0017] Another aspect of the present application provides a method for generating a qubit drive signal, wherein the qubit drive signal is used to control the quantum state information of a qubit on a quantum chip, and the qubit drive signal is obtained by processing an intermediate frequency signal and a microwave signal; the method comprising:

[0018] Obtain multiple microwave signals of different frequencies; wherein the frequencies of the microwave signals correspond to the frequencies of the qubit drive signals; determine a phase coherence point based on the frequencies or phases of the two microwave signals, and output a trigger signal based on the phase coherence point; wherein the phase coherence point is the moment when the phase difference between the two microwave signals is consistent; generate an intermediate frequency signal corresponding to the multiple qubit drive signals in response to the trigger signal; and output the multiple qubit drive signals based on the multiple intermediate frequency signals and the multiple microwave signals.

[0019] The method for generating a qubit drive signal as described above, further comprising obtaining multiple microwave signals of different frequencies, comprising: obtaining multiple first microwave signals of different frequencies and multiple second microwave signals of different frequencies; wherein the frequency of the first microwave signal is lower than the frequency of the second microwave signal.

[0020] The method for generating a qubit drive signal as described above, further comprising determining a phase coherence point based on the frequencies of the two microwave signals and generating a trigger signal according to the phase coherence point, comprising: determining a frequency difference between the two microwave signals; determining the inverse of the frequency difference as a trigger period of the phase coherence point; and generating the trigger signal based on the trigger period.

[0021] In the above-described method for generating a qubit drive signal, further, when the first microwave signal and the second microwave signal correspond to different qubit drive signals, respectively, determining the frequency difference between the two microwave signals includes: determining the frequency difference between the first microwave signal and the second microwave signal.

[0022] In the method for generating a qubit drive signal as described above, further, when the first microwave signal and the second microwave signal correspond to the same qubit drive signal, determining the frequency difference between the two microwave signals includes: determining the frequency difference between two first microwave signals of different frequencies; wherein the two first microwave signals respectively correspond to qubit drive signals of different frequencies.

[0023] The method for generating a qubit drive signal as described above, further, when the first microwave signal and the second microwave signal correspond to the same qubit drive signal, determining the frequency difference between the two microwave signals further includes: determining two second microwave signals based on the frequency difference between the two first microwave signals; wherein the frequency difference between the two second microwave signals is an integer multiple of the frequency difference between the two first microwave signals.

[0024] The method for generating a qubit drive signal as described above, further comprising: generating the trigger signal based on the trigger period, comprising: generating the trigger signal at a time that is an integer multiple of the trigger period.

[0025] The method for generating a qubit drive signal as described above, further, determining a phase coherence point based on the phases of the two microwave signals, and generating a trigger signal according to the phase coherence point, includes: determining the phase difference between the first microwave signal and the second microwave signal at the same moment as a preset phase difference; obtaining the current phase difference between the first microwave signal and the second microwave signal; determining the moment when the current phase difference and the preset phase difference are the same as the phase coherence point, and outputting the trigger signal at the phase coherence point.

[0026] The method for generating a qubit drive signal as described above, further, determining a phase coherence point based on the phases of the two microwave signals, and generating a trigger signal according to the phase coherence point, includes: determining a preset phase difference based on the difference between the first phase difference of the two first microwave signals and the second phase difference of the two second microwave signals at the same moment; obtaining the current first phase difference of the two first microwave signals, and the current second phase difference of the two second microwave signals; determining the moment when the difference between the current first phase difference and the current second phase difference is the same as the preset phase difference as the phase coherence point, and outputting the trigger signal at the phase coherence point.

[0027] On another aspect, the present application provides a quantum computer, comprising the above-mentioned device for generating a qubit drive signal, or using the above-mentioned method for generating a qubit drive signal to generate a qubit drive signal for controlling the quantum state information of a qubit on a quantum chip.

[0028] Compared with the prior art, the quantum bit drive signal to be generated in the present application is obtained by processing the intermediate frequency signal and the microwave signal; multiple microwave signals of different frequencies are output through the microwave source module; wherein the frequency of the microwave signal corresponds to the frequency of the quantum bit drive signal; and the microwave source module is connected through the control module, and the phase coherence point is determined based on the frequency or phase of the two microwave signals, and a trigger signal is output according to the phase coherence point; wherein the phase coherence point is the moment when the phase difference of the two microwave signals is consistent; then, the waveform output module responds to the trigger signal to output the intermediate frequency signal corresponding to the multiple quantum bit drive signals; since the phase difference of the two microwave signals is consistent at this time; therefore, the phases of the multiple quantum bit drive signals output by the signal processing module based on the multiple intermediate frequency signals and the multiple microwave signals are coherent. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a diagram showing the composition of a device for generating a quantum bit drive signal according to an embodiment of the present application;

[0030] Figure 2 A diagram showing the composition of a microwave source module according to an embodiment of the present application;

[0031] Figure 3 A composition diagram of a control module according to an embodiment of the present application;

[0032] Figure 4 A composition diagram of another control module according to an embodiment of the present application;

[0033] Figure 5 This is a composition diagram of another control module according to an embodiment of the present application;

[0034] Figure 6 This is a flow chart of a method for generating a quantum bit drive signal according to an embodiment of the present application;

[0035] Figure 7 This is a flow chart of an embodiment of the present application for generating a trigger signal based on the frequency of multiple microwave signals;

[0036] Figure 8 This is a flow chart of generating a trigger signal based on the phase of multiple microwave signals according to an embodiment of the present application;

[0037] Figure 9 This is another flowchart of generating a trigger signal based on the phase of multiple microwave signals according to an embodiment of the present application.

[0038] Explanation of the accompanying drawings: 1-microwave source module, 2-control module, 3-waveform output module, 4-signal processing module, 11-first microwave source, 12-second microwave source, 201-frequency difference determination unit, 202-trigger period determination unit, 203-first trigger unit, 211-first phase difference determination unit, 212-first phase measurement unit, 213-second trigger unit, 221-second phase difference determination unit, 222-second phase measurement unit, 223-third trigger unit. DETAILED DESCRIPTION

[0039] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application.

[0040] The operating frequency of a quantum chip is relatively high, usually set at around 6 GHz. The frequency of the qubit driving signal that drives the qubit on the quantum chip is also around 6 GHz. The frequency of the driving signal that drives the qubit corresponds one-to-one with the operating frequency of the qubit to achieve the optimal qubit driving effect.

[0041] The intermediate frequency signal, which carries the modulation and coding information needed to drive the qubits, is too low to drive the qubits. Therefore, mixing the intermediate frequency signal is necessary to generate a high-frequency signal capable of driving the qubits. Specifically, the required qubit drive signal is obtained by mixing the intermediate frequency signal with a microwave signal.

[0042] The operating frequencies of the qubits on a quantum chip can be the same or different. When the qubits operate at different frequencies, the frequencies of the qubit drive signals will also be different. When the frequencies of the qubit drive signals to be generated are different, the corresponding microwave signals will also have different frequencies. Microwave signals of different frequencies will have phase differences, and this phase difference will vary over time, resulting in phase incoherence of the microwave signals and, in turn, phase incoherence of the generated multi-qubit drive signals.

[0043] like Figure 1 As shown, an embodiment of the present application provides a device for generating a qubit drive signal, wherein the qubit drive signal is obtained by processing an intermediate frequency signal and a microwave signal; the generating device includes: a microwave source module, configured to output multiple microwave signals of different frequencies; wherein the frequency of the microwave signal corresponds to the frequency of the qubit drive signal; a control module, connected to the microwave source module, configured to determine a phase coherence point based on the frequency or phase of the two microwave signals, and output a trigger signal based on the phase coherence point; wherein the phase coherence point is the moment when the phase difference between the two microwave signals is consistent; a waveform output module, connected to the control module, configured to output an intermediate frequency signal corresponding to the multiple qubit drive signals in response to the trigger signal; a signal processing module, connected to the microwave source module and the waveform output module, configured to output multiple qubit drive signals based on the multiple intermediate frequency signals and the multiple microwave signals. It should be noted that the intermediate frequency signal carries information of a preset target for driving the quantum state change of the qubit. Exemplarily, the preset target for the quantum state change of the qubit can be represented by a quantum logic gate or a sequence of quantum logic gates.

[0044] The present application outputs multiple microwave signals of different frequencies through a microwave source module 1; then the microwave source module 1 is connected through a control module 2 to obtain the frequency or phase parameters of the multiple microwave signals of different frequencies, and a phase coherence point at which the phase difference of the multiple microwave signals is consistent is determined by the frequency or phase parameters, wherein the phase coherence point can be understood as the phase difference of the multiple microwave signals at a certain moment being the same as the initial phase difference, that is, the phase of the multiple microwave signals at this time is coherent; and a trigger signal is output to the waveform output module 3 at this point. When the waveform output module 3 receives the trigger signal, it outputs multiple intermediate frequency signals to the signal processing module 4. The signal processing module 4 performs mixing processing based on the currently received multiple intermediate frequency signals and multiple microwave signals. Since the phases of the current multiple microwave signals are coherent, the phases between the multiple quantum bit drive signals output by the signal processing module 4 are also coherent. Among them, the control module 2 of the present application can adopt FPGA (Field-Programmable Gate Array), that is, field programmable gate array.

[0045] In addition, since the multi-channel first microwave signals are periodic signals, the corresponding phase coherence points will also show periodicity. After the control module 2 obtains the phase coherence points of the multi-channel microwave signals, it repeatedly outputs the trigger signal to the waveform output module 3 according to the period of the phase coherence points, thereby ensuring that the phases between the multi-channel quantum bit drive signals output by the signal processing module 4 each time are coherent. As is known to all, the quantum state information of the quantum bit is a probability distribution, and the drive of the quantum bit needs to be repeated many times. Therefore, the quantum bit drive signal generation device of the present application can also improve the calculation accuracy of the quantum chip.

[0046] like Figure 2 As shown, as an implementation of an embodiment of the present application, the microwave source module 1 includes a first microwave source 11 and a second microwave source 12, wherein the frequency of the first microwave signal output by the first microwave source 11 is lower than the frequency of the second microwave signal output by the second microwave source 12.

[0047] When the operating frequencies of the qubits on a quantum chip differ, and the number of qubits increases significantly, the operating bandwidth of the quantum chip and the bandwidth of the qubit drive signal increase. For example, the operating bandwidth of a quantum chip with an operating frequency of 4-6 GHz has already reached 2 GHz. With technological advancements, even wider bandwidths may be achieved in the future. By providing microwave signals of different frequency bands through first microwave source 11 and second microwave source 12 and expanding the number of first microwave sources 11 and second microwave sources 12, the bandwidth of the microwave signal used for frequency mixing is increased, enabling the generation of qubit drive signals with wider bandwidths, thereby facilitating the expansion of the number of qubits on the quantum chip.

[0048] Since the first microwave source 11 and the second microwave source 12 are used, and the frequencies of the multiple microwave signals output by the first microwave source 11 and the second microwave source 12 are different, that is, the phase differences of the multiple microwave signals are inconsistent, the phases of the generated multi-channel quantum bit drive signals will be incoherent. It is necessary to use a control module to determine the phase coherence point based on the frequency or phase of the multiple microwave signals, and output a trigger signal based on the period of the phase coherence point to ensure that the phase of the multi-channel quantum bit drive signal generated by the signal processing module is also coherent.

[0049] like Figure 3 As shown, as one of the implementation methods, when the control module determines the phase coherence point based on the frequencies of the two microwave signals and outputs the trigger signal according to the phase coherence point, the control module 2 includes: a frequency difference determination unit 201, used to determine the frequency difference of the two microwave signals; a trigger period determination unit 202, used to determine the inverse of the frequency difference as the trigger period of the phase coherence point; and a first trigger unit 203, used to output the trigger signal based on the trigger period.

[0050] The frequencies of the two microwave signals output by the microwave source module 1 are 5.0 GHz and 5.2 GHz respectively, wherein the initial phases of the two microwave signals may be the same or different; this embodiment takes the same phase of the two microwave signals at the initial moment as an example; the frequency difference between the two microwave signals is determined to be 200 MHz by the frequency difference determination unit 201, and the reciprocal of the frequency difference is determined to be the trigger period of the phase coherence point, that is, the reciprocal of 200 MHz is 0.5 ns by the trigger period determination unit 202; wherein, the phase coherence point means that every 0.5 ns, the current phase difference of the two microwave signals is the same as the initial phase difference, that is, the current phases of the two microwave signals are also coherent; finally, the first trigger unit 203 outputs a trigger signal to the waveform output module 3 according to the trigger period of the phase coherence point of 0.5 ns, and the waveform output module 3 outputs an intermediate frequency signal to the signal processing module 4 in response to the trigger signal, to ensure that the phases of the two quantum bit drive signals generated by the signal processing module 4 are also coherent.

[0051] It should be noted that when mixing a microwave signal with an intermediate frequency signal to generate a qubit drive signal, either IQ mixing or secondary frequency conversion can be used. When using IQ mixing, both the first microwave signal output by the first microwave source 11 and the second microwave signal output by the second microwave source 12 can serve as local oscillator signals. When using secondary frequency conversion, the first microwave signal serves as the local oscillator signal for the first frequency conversion, while the second microwave signal serves as the local oscillator signal for the second frequency conversion.

[0052] When using IQ mixing technology to generate qubit drive signals, the first microwave signal and the second microwave signal correspond to different qubit drive signals, respectively. The frequency difference determination unit 201 is used to determine the frequency difference between the first microwave signal and the second microwave signal. Specifically, due to the different frequencies of the first microwave signal and the second microwave signal, the phases of the generated multiple qubit drive signals of different frequencies are incoherent. The frequency difference determination unit 201 determines the frequency difference between the first and second microwave signals, and the trigger period determination unit 202 determines the inverse of the frequency difference between the first and second microwave signals as the trigger period of the phase coherence point. The first trigger unit 203 then outputs a trigger signal to the signal processing module at the trigger period of the phase coherence point of the first and second microwave signals. Since the phases of the first and second microwave signals are coherent at this time, the phases of the multiple qubit drive signals obtained by mixing via the signal processing module 4 are also coherent.

[0053] When the secondary frequency conversion technology is used to generate the qubit drive signal, the first microwave signal and the second microwave signal correspond to the same qubit drive signal, and the frequency difference determination unit 201 is used to: determine the frequency difference between the two first microwave signals of different frequencies; wherein the two first microwave signals respectively correspond to qubit drive signals of different frequencies.

[0054] Specifically, when using the secondary frequency conversion technology to generate multiple qubit drive signals of different frequencies, since the frequencies of the multiple first micro signals are different and the frequencies of the multiple second micro signals are also different, the phases of the multiple first micro signals of different frequencies are incoherent, and the phases of the multiple second micro signals of different frequencies are also incoherent, resulting in the phases of the generated multiple qubit drive signals of different frequencies being incoherent. The frequency difference determination unit 201 determines the frequency difference of the two first microwave signals of different frequencies, and the trigger period determination unit 202 determines the inverse of the frequency difference of the two first microwave signals as the trigger period of the phase coherence point. At this time, the first trigger unit 203 outputs a trigger signal to the signal processing module 4. Since the phases of the two first microwave signals are coherent at this time, the phases of the multiple RF signals to be processed by the secondary frequency conversion output by the signal processing module 4 through the first frequency conversion processing are coherent.

[0055] When the signal processing module performs the second frequency conversion processing, the second microwave source 12 outputs two second microwave signals based on the frequency difference between the two first microwave signals; wherein the frequency difference between the two second microwave signals is an integer multiple of the frequency difference between the two first microwave signals.

[0056] Specifically, since the phase coherence point of two first microwave signals of different frequencies is determined by the frequency difference between the two first microwave signals, when the frequency difference between the two second microwave signals output by the second microwave source 12 is set to an integer multiple of the frequency difference between the two first microwave signals, and since the trigger period of the phase coherence point is obtained by the derivative of the frequency difference, it can be understood that the trigger period of the phase coherence point of the two first microwave signals is an integer multiple of the period of the phase coherence point of the two second microwave signals. That is, when the phase coherence point of the two first microwave signals is used, the two second microwave signals are also necessarily at the phase coherence point. This ensures that when the first trigger unit 203 outputs a trigger signal based on the period of the phase coherence point of the two first microwave signals, the phases of the two first microwave signals and the two second microwave signals are coherent, so that the phases of the multi-qubit drive signals generated by the signal processing module 4 through secondary frequency conversion are also coherent.

[0057] Specifically, the first trigger unit 203 is configured to output the trigger signal at an integer multiple of the trigger period. The trigger period ensures the current phase coherence of the multi-channel microwave signals. Therefore, the first trigger unit 203 outputs the trigger signal at an integer multiple of the trigger period, such as 1, 2, or 3 times the trigger period. Taking the aforementioned 0.5 ns trigger period as an example, the first trigger unit 203 can output the trigger signal at 0.5 ns, 1 ns, or 5 ns, etc., to ensure the current phase coherence of the multi-channel microwave signals and achieve triggering flexibility.

[0058] As described above, when IQ mixing technology is used to generate quantum bit drive signals, not only can the frequency difference between the first microwave signal and the second microwave signal be used to determine the phase coherence point, and based on the phase coherence point output trigger signal to enable the signal processing module 4 to generate multiple phase-coherent quantum bit drive signals, but the phase difference between the first microwave signal and the second microwave signal can also be used to achieve phase coherence of the multiple quantum bit drive signals generated by the signal processing module 4. The specific implementation method is described below.

[0059] like Figure 4 As shown, as another embodiment, when the control module 2 determines the phase coherence point based on the phases of the two microwave signals and outputs the trigger signal according to the phase coherence point, the control module 1 includes: a first phase difference determination unit 211, used to determine the phase difference between the first microwave signal and the second microwave signal at the same time as the preset phase difference; a first phase measurement unit 212, used to obtain the current phase difference between the first microwave signal and the second microwave signal; a second trigger unit 213, used to determine the moment when the current phase difference and the preset phase difference are the same as the phase coherence point, and output the trigger signal at the phase coherence point.

[0060] For example, the frequency of the first microwave signal output by the first microwave source 11 is 5.0 GHz, and the frequency of the second microwave signal output by the second microwave source 12 is 5.2 GHz. The initial phases of the first microwave signal and the second microwave signal can be the same or different, which can be achieved by setting the output parameters of the first microwave source 11 and the second microwave source 12. In the implementation of this application, the initial phases are the same. The first phase difference determination unit 211 determines the phase difference of the first microwave signal and the second microwave signal at the same time as a preset phase difference of 90 degrees; the first phase measurement unit 212 measures the current phase difference of the first microwave signal and the second microwave signal in real time; by using the preset phase difference as a reference and comparing the current phase difference with the preset phase difference by the second trigger unit 213, it is determined that the moment when the current phase difference is the same as the preset phase difference is the phase coherence point, and a trigger signal is output at this moment. Since the phase difference of the first microwave signal and the second microwave signal input to the signal processing module 4 at the current moment is consistent, that is, coherent, the phases of the two qubit drive signals generated by the signal processing module 4 are ensured to be coherent.

[0061] As mentioned above, when the secondary frequency conversion technology is used to generate multi-channel quantum bit drive signals, not only can the frequency difference between the two first microwave signals and the frequency difference between the two second microwave signals be used to realize the multi-channel phase-coherent quantum bit drive signals generated by the signal processing module 4, but the phase difference between the multiple first microwave signals and the multiple second microwave signals can also be used to realize the phase coherence of the multi-channel quantum bit drive signals generated by the signal processing module 4. The specific implementation method is described below.

[0062] like Figure 5 As shown, as another embodiment, when the control module 2 determines the phase coherence point based on the phase of the two microwave signals and outputs the trigger signal according to the phase coherence point, the control module 2 includes: a second phase difference determination unit 221, used to determine the difference between the first phase difference of the two first microwave signals and the second phase difference of the two second microwave signals at the same time as the preset phase difference; a second phase measurement unit 222, used to obtain the current first phase difference of the two first microwave signals and the current second phase difference of the two second microwave signals; a third trigger unit 223, used to determine the moment when the difference between the current first phase difference and the current second phase difference is the same as the preset phase difference as the phase coherence point, and output the trigger signal at the phase coherence point.

[0063] Specifically, not only does a phase difference exist between the two first microwave signals, but there is also a phase difference between the two second microwave signals. First, the second phase difference determining unit 221 determines the first phase difference between the two first microwave signals and the second phase difference between the two second microwave signals at a certain moment, and determines that the difference between the first phase difference and the second phase difference is a fixed value, which is used as the preset phase difference. The fixed value can be 0 or other values. Then, the second phase measuring unit 222 measures the current first phase difference of the first microwave signal and the current second phase difference of the two second microwave signals in real time, and sends the current first phase difference and the current second phase difference to the third triggering unit 223. The third triggering unit 223 determines the difference between the current first phase difference and the current second phase difference through calculation, and compares the difference with the preset phase difference. When the difference is the same as the preset phase difference, it is determined that the moment is a phase coherence point. At this time, the phases of the two first microwave signals are coherent and the phases of the two second microwave signals are coherent. A trigger signal is output at the phase coherence point to ensure the phase coherence of the multi-channel quantum bit drive signal generated by the signal processing module 4.

[0064] The first phase measurement unit 212 and the second phase measurement unit 222 may employ a phase detector. The phase detector has advantages such as high sensitivity and stable performance, ensuring that the measured current phase value is accurate and has a small error, thereby ensuring the accuracy of the trigger signal and improving the phase coherence accuracy of the multi-channel qubit drive signal generated by the signal processing module 4.

[0065] As one embodiment of the present application, the waveform output module 3 includes at least two waveform generators, each of which is configured to output at least one intermediate frequency signal in response to the trigger signal. It is understood that each qubit drive signal corresponds to several microwave signals and several intermediate frequency signals. Multiple waveform generators are employed, each capable of outputting several intermediate frequency signals in response to the trigger signal, for the signal processing module 4 to generate more qubit drive signals, thereby adapting to the driving requirements of a multi-bit quantum chip.

[0066] When the control module 2 of the present application sends a trigger signal to multiple waveform generators, the control module 2 sends the trigger signal to each of the waveform generators simultaneously. By sending the trigger signal simultaneously, it is ensured that the intermediate frequency signal output by each waveform generator to the signal processing module 4 is synchronized, and the phases of the multiple microwave signals output by the microwave source module 1 to the signal processing module 4 are coherent, ensuring that the phases of the multi-channel quantum bit drive signals output by the signal processing module 4 are all coherent.

[0067] As an implementation method of an embodiment of the present application, the signal processing module 4 includes at least two mixing units, each of which is used to: output one qubit drive signal based on the two intermediate frequency signals and one first microwave signal; or output one qubit drive signal based on the two intermediate frequency signals and one second microwave signal.

[0068] Specifically, when using IQ mixing technology to generate qubit drive signals, the first microwave source 11 outputs multiple first microwave signals, and the second microwave source 12 outputs multiple second microwave signals. Each mixing unit mixes one first microwave signal with two intermediate frequency signals, or one second microwave signal with two intermediate frequency signals, to ensure the driving requirements of the multi-bit quantum chip.

[0069] In addition, when the secondary frequency conversion technology is used to generate the qubit drive signal, the signal processing module 4 includes at least two mixing units, each of which is used to output the qubit drive signal based on one intermediate frequency signal, one first microwave signal, and one second microwave signal.

[0070] like Figure 6 As shown, the embodiment of the present application further provides a method for generating a qubit drive signal, wherein the qubit drive signal is used to control the quantum state information of the qubit on the quantum chip, and the qubit drive signal is obtained by processing an intermediate frequency signal and a microwave signal; the method comprises the following steps:

[0071] Step S10: obtaining multiple microwave signals of different frequencies; wherein the frequencies of the microwave signals correspond to the frequencies of the qubit drive signals.

[0072] Step S20: determining a phase coherence point based on the frequencies or phases of the two microwave signals, and outputting a trigger signal according to the phase coherence point; wherein the phase coherence point is the moment when the phase difference of the two microwave signals is consistent.

[0073] Step S30: generating an intermediate frequency signal corresponding to the multiple qubit drive signals in response to the trigger signal.

[0074] Step S40: outputting multiple channels of the qubit driving signals based on the multiple channels of the intermediate frequency signals and the multiple channels of the microwave signals.

[0075] Specifically, each qubit drive signal needs to be obtained by mixing several microwave signals and several intermediate frequency signals. Since the qubits on the quantum chip operate at different frequencies, the frequencies of the corresponding qubit drive signals will also be different. Therefore, the frequencies of the microwave signals corresponding to each qubit drive signal will also be different.

[0076] Taking two qubit drive signals of different frequencies as an example, when generating the two qubit drive signals, the corresponding multi-channel microwave signals of different frequencies are first determined; and a phase coherence point of the multi-channel microwave signals is determined according to the frequency or phase of the multi-channel microwave signals, and a trigger signal is generated at the phase coherence point, wherein the phase coherence point can be understood as the phase difference of the multi-channel microwave signals at a certain moment is the same as the initial phase difference, that is, the phase of the multi-channel microwave signals is coherent at this time; then, according to the trigger signal, the intermediate frequency signals corresponding to the two qubit drive signals are generated, and mixed with the multi-channel microwave signals respectively. Since the phases of the current first microwave signal and the second microwave signal are coherent, the phases of the qubit drive signals generated by mixing are also coherent.

[0077] Specifically, obtaining multiple microwave signals of different frequencies includes obtaining multiple first microwave signals of different frequencies and multiple second microwave signals of different frequencies; wherein the frequency of the first microwave signal is lower than the frequency of the second microwave signal. Using the first and second microwave signals in different frequency bands increases the bandwidth of the microwave signal used for frequency mixing, enabling the generation of a wider-bandwidth qubit drive signal, thereby facilitating the expansion of qubits on a quantum chip.

[0078] like Figure 7 As shown, as an implementation method of an embodiment of the present application, determining a phase coherence point based on the frequencies of the two microwave signals and generating a trigger signal according to the phase coherence point includes the following steps:

[0079] Step S201: Determine the frequency difference between two microwave signals.

[0080] Step S202: Determine the reciprocal of the frequency difference as the trigger period of the phase coherent point.

[0081] Step S203: Generate the trigger signal based on the trigger period.

[0082] Specifically, the frequencies of the two corresponding microwave signals and the corresponding frequency difference are determined based on the frequency parameters of the two qubit drive signals to be generated. The initial phases of the multiple microwave signals can be the same or different. For example, if the initial phases of the multiple microwave signals are the same, the phases of the multiple microwave signals are initially coherent. The trigger period of the phase coherence point is obtained by calculating the inverse of the frequency difference. At each trigger period, the current phase difference of the multiple microwave signals is the same as the initial phase difference, meaning that the phases of the multiple microwave signals are coherent at the current moment. At this point, a trigger signal is generated, and the intermediate frequency signal used for mixing is output via the trigger signal, ensuring that the phases of the two qubit drive signals generated by mixing are also coherent.

[0083] When the IQ mixing technology is used to generate the qubit drive signal, and the first microwave signal and the second microwave signal correspond to different qubit drive signals respectively, determining the frequency difference between the two microwave signals includes: determining the frequency difference between the first microwave signal and the second microwave signal.

[0084] Specifically, the frequency difference between the first microwave signal and the second microwave signal is first determined, and the inverse of the frequency difference between the first microwave signal and the second microwave signal is used as the trigger period of the phase coherence point. Then, a trigger signal is output at the trigger period of the phase coherence point of the first microwave signal and the second microwave signal. Since the phases of the first microwave signal and the second microwave signal are coherent at this time, the phases of the two quantum bit drive signals generated are also coherent.

[0085] When the qubit drive signal is generated using secondary frequency conversion technology, the first microwave signal and the second microwave signal correspond to the same qubit drive signal, and determining the frequency difference between the two microwave signals includes: determining the frequency difference between two first microwave signals of different frequencies; wherein the two first microwave signals respectively correspond to qubit drive signals of different frequencies.

[0086] Specifically, the frequency difference of two first microwave signals of different frequencies is determined, and the inverse of the frequency difference of the two first microwave signals is determined as the trigger period of the phase coherence point. At this time, a trigger signal is output. Since the phases of the two first microwave signals are coherent at this time, the phases of the multiple radio frequency signals to be processed by the secondary frequency conversion output through the first frequency conversion processing are coherent.

[0087] When performing the second frequency conversion processing, determining the frequency difference between the two microwave signals further includes: determining two second microwave signals based on the frequency difference between the two first microwave signals; wherein the frequency difference between the two second microwave signals is an integer multiple of the frequency difference between the two first microwave signals.

[0088] Specifically, when the frequency difference between the two second microwave signals is set to an integer multiple of the frequency difference between the two first microwave signals, since the trigger period of the phase coherence point is obtained by the derivative of the frequency difference, it can be understood that the trigger period of the phase coherence point of the two first microwave signals is an integer multiple of the period of the phase coherence point of the two second microwave signals. That is, when the phase coherence point of the two first microwave signals is used, the two second microwave signals must also be at the phase coherence point. This ensures that when the trigger signal is output based on the period of the phase coherence point of the two first microwave signals, the phases of the two first microwave signals and the two second microwave signals are coherent, so that the phase of the generated multi-qubit drive signal is also coherent.

[0089] As an implementation method of an embodiment of the present application, generating the trigger signal based on the trigger period includes: generating the trigger signal at an integer multiple of the trigger period. Specifically, the trigger period is used to achieve current phase coherence of the multi-channel microwave signals. Therefore, by outputting the trigger signal at an integer multiple of the trigger period, such as outputting the trigger signal at 1, 2, or 3 times the trigger period, the current phase coherence of the multi-channel microwave signals can also be ensured, thereby achieving triggering flexibility.

[0090] like Figure 8 As shown, as an implementation method of an embodiment of the present application, when the IQ mixing technology is used to generate the quantum bit drive signal, the phase coherence point is determined based on the phase of the two microwave signals, and the trigger signal is generated according to the phase coherence point, including the following steps:

[0091] Step S211: determining a phase difference between the first microwave signal and the second microwave signal at the same moment as a preset phase difference;

[0092] Step S212: obtaining a current phase difference between the first microwave signal and the second microwave signal;

[0093] Step S213: Determine the moment when the current phase difference is the same as the preset phase difference as the phase coherence point, and output the trigger signal at the phase coherence point.

[0094] Specifically, by determining the phase difference between the first microwave signal and the second microwave signal at the same moment as a preset phase difference; and obtaining the current phase difference between the first microwave signal and the second microwave signal in real time; and then using the preset phase difference as a reference, comparing the current phase difference with the preset phase difference, and generating a trigger signal when the current phase difference is the same as the preset phase difference, it is ensured that the phase difference between the first microwave signal and the second microwave signal at the current moment is consistent with the preset phase difference, that is, coherent, thereby ensuring that the phase of the generated multi-channel quantum bit drive signal is coherent.

[0095] like Figure 9 As shown, as an implementation method of an embodiment of the present application, when a qubit drive signal is generated using a secondary frequency conversion technology, the phase coherence point is determined based on the phases of the two microwave signals, and a trigger signal is generated according to the phase coherence point, including the following steps:

[0096] Step S221: determining a preset phase difference according to a difference between a first phase difference of the two first microwave signals and a second phase difference of the two second microwave signals at the same time.

[0097] Step S222: Obtain a current first phase difference between the two first microwave signals and a current second phase difference between the two second microwave signals.

[0098] Step S223: Determine the moment when the difference between the current first phase difference and the current second phase difference is the same as the preset phase difference as the phase coherence point, and output the trigger signal at the phase coherence point.

[0099] Specifically, a first phase difference between the two first microwave signals and a second phase difference between the two second microwave signals at a certain moment is first determined, and the difference between the first phase difference and the second phase difference is determined to be a fixed value, and the fixed value is used as the preset phase difference; then, the current first phase difference of the first microwave signal and the current second phase difference of the two second microwave signals are measured in real time; the difference between the current first phase difference and the current second phase difference is determined by calculation, and the difference is compared with the preset phase difference. When the difference is the same as the preset phase difference, the moment is determined to be a phase coherence point. At this time, the phases of the two first microwave signals are coherent and the phases of the two second microwave signals are coherent. A trigger signal is output at the phase coherence point to ensure the phase coherence of the generated multi-qubit drive signal.

[0100] Based on the same application concept, an embodiment of the present application also provides a quantum computer, including the above-mentioned device for generating a quantum bit drive signal, or using the above-mentioned method for generating a quantum bit drive signal to generate a quantum bit drive signal for controlling the quantum state information of the quantum bit on the quantum chip.

[0101] Compared with the prior art, the qubit drive signal of the present application is used to control the quantum state information of the qubit on the quantum chip. The qubit drive signal is obtained by processing the intermediate frequency signal and the microwave signal; first, multiple microwave signals of different frequencies are output; and the phase coherence point of the first microwave signal and the second microwave signal is determined based on the frequency or phase of the two microwave signals, wherein the phase coherence point is the moment when the phase difference between the first microwave signal and the second microwave signal is consistent; and a trigger signal is output according to the phase coherence point; in response to the trigger signal, an intermediate frequency signal corresponding to the qubit drive signal to be generated is output, and the intermediate frequency signal is mixed with the first microwave signal and the intermediate frequency signal and the second microwave signal respectively, so that the phase of the multi-channel qubit drive signal output after the mixing process is coherent.

[0102] The above describes in detail the structure, features and effects of the present application based on the embodiments shown in the drawings. The above is only a preferred embodiment of the present application, but the present application does not limit the scope of implementation to what is shown in the drawings. Any changes made in accordance with the concept of the present application, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the description and drawings, should be within the scope of protection of the present application.

Claims

1. A device for generating a quantum bit drive signal, characterized in that: The qubit drive signal is obtained by processing an intermediate frequency signal and a microwave signal; the generating device includes: A microwave source module, configured to output multiple microwave signals of different frequencies; wherein the frequencies of the microwave signals correspond to the frequencies of the qubit drive signals; a control module connected to the microwave source module, configured to determine a phase coherence point based on the frequencies or phases of the two microwave signals, and output a trigger signal according to the phase coherence point; wherein the phase coherence point is the moment when the phase difference of the two microwave signals is consistent; A waveform output module, connected to the control module, configured to output an intermediate frequency signal corresponding to the multiple qubit drive signals in response to the trigger signal; A signal processing module is connected to the microwave source module and the waveform output module, and is used to output multiple qubit driving signals based on the multiple intermediate frequency signals and the multiple microwave signals.

2. The device for generating a quantum bit drive signal according to claim 1, wherein: The microwave source module includes a first microwave source and a second microwave source, wherein a frequency of a first microwave signal output by the first microwave source is lower than a frequency of a second microwave signal output by the second microwave source.

3. The device for generating a quantum bit drive signal according to claim 2, wherein: When the control module determines a phase coherence point based on the frequencies of the two microwave signals and outputs a trigger signal according to the phase coherence point, the control module includes: a frequency difference determining unit, configured to determine a frequency difference between the two microwave signals; a trigger period determining unit, configured to determine the reciprocal of the frequency difference as the trigger period of the phase coherent point; The first trigger unit is configured to output the trigger signal based on the trigger period.

4. The device for generating a quantum bit drive signal according to claim 3, wherein: The first microwave signal and the second microwave signal correspond to different qubit drive signals, respectively, and the frequency difference determining unit is configured to: A frequency difference between the first microwave signal and the second microwave signal is determined.

5. The device for generating a quantum bit drive signal according to claim 3, wherein: The first microwave signal and the second microwave signal correspond to the same qubit drive signal, and the frequency difference determining unit is configured to: Determine a frequency difference between two first microwave signals of different frequencies; wherein the two first microwave signals correspond to qubit drive signals of different frequencies, respectively.

6. The device for generating a quantum bit drive signal according to claim 5, wherein: The second microwave source is configured to output two second microwave signals based on a frequency difference between the two first microwave signals; wherein the frequency difference between the two second microwave signals is an integer multiple of the frequency difference between the two first microwave signals.

7. The device for generating a qubit drive signal according to claim 3, wherein: The first trigger unit is configured to output the trigger signal at a time that is an integer multiple of the trigger period.

8. The device for generating a quantum bit drive signal according to claim 2, wherein: When the control module determines a phase coherence point based on the phases of the two microwave signals and outputs a trigger signal according to the phase coherence point, the control module includes: a first phase difference determining unit, configured to determine a phase difference between the first microwave signal and the second microwave signal at the same moment as a preset phase difference; a first phase measurement unit, configured to obtain a current phase difference between the first microwave signal and the second microwave signal; The second trigger unit is configured to determine a moment when the current phase difference is the same as the preset phase difference as the phase coherence point, and output the trigger signal at the phase coherence point.

9. The device for generating a qubit drive signal according to claim 2, wherein: When the control module determines a phase coherence point based on the phases of the two microwave signals and outputs a trigger signal according to the phase coherence point, the control module includes: a second phase difference determining unit, configured to determine a difference between a first phase difference between the two first microwave signals and a second phase difference between the two second microwave signals at the same moment as a preset phase difference; a second phase measurement unit, configured to obtain a current first phase difference between the two first microwave signals and a current second phase difference between the two second microwave signals; The third trigger unit is used to determine the moment when the difference between the current first phase difference and the current second phase difference is the same as the preset phase difference as the phase coherence point, and output the trigger signal at the phase coherence point.

10. The device for generating a quantum bit drive signal according to claim 1, wherein: The waveform output module includes at least two waveform generators, each waveform generator is used to output at least one intermediate frequency signal in response to the trigger signal.

11. The device for generating a quantum bit drive signal according to claim 10, wherein: The control module sends the trigger signal to each of the waveform generators simultaneously.

12. The device for generating a qubit drive signal according to claim 2, wherein: The signal processing module includes at least two mixing units, each of which is configured to: Outputting one qubit driving signal based on the two intermediate frequency signals and one first microwave signal; or A qubit driving signal is output based on the two intermediate frequency signals and the second microwave signal.

13. The device for generating a quantum bit drive signal according to claim 2, wherein: The signal processing module includes at least two frequency mixing units, each of which is configured to: A qubit driving signal is output based on the intermediate frequency signal, the first microwave signal, and the second microwave signal.

14. A method for generating a qubit drive signal, wherein the qubit drive signal is used to control the quantum state information of a qubit on a quantum chip, and the qubit drive signal is obtained by processing an intermediate frequency signal and a microwave signal; characterized in that: The method comprises: Obtaining multiple microwave signals of different frequencies; wherein the frequencies of the microwave signals correspond to the frequencies of the qubit drive signals; Determining a phase coherence point based on the frequencies or phases of the two microwave signals, and outputting a trigger signal according to the phase coherence point; wherein the phase coherence point is the moment when the phase difference of the two microwave signals is consistent; generating an intermediate frequency signal corresponding to the multiple qubit drive signals in response to the trigger signal; Based on the multiple intermediate frequency signals and the multiple microwave signals, multiple qubit driving signals are output.

15. The method for generating a qubit drive signal according to claim 14, wherein: The obtaining of multiple microwave signals of different frequencies comprises: A plurality of first microwave signals with different frequencies and a plurality of second microwave signals with different frequencies are obtained; wherein the frequency of the first microwave signal is lower than the frequency of the second microwave signal.

16. The method for generating a quantum bit drive signal according to claim 15, wherein: The determining of a phase coherence point based on the frequencies of the two microwave signals and generating a trigger signal according to the phase coherence point includes: determining a frequency difference between the two microwave signals; Determining the reciprocal of the frequency difference as the trigger period of the phase coherent point; The trigger signal is generated based on the trigger period.

17. The method for generating a qubit drive signal according to claim 16, wherein: When the first microwave signal and the second microwave signal correspond to different qubit drive signals, respectively, determining the frequency difference between the two microwave signals includes: A frequency difference between the first microwave signal and the second microwave signal is determined.

18. The method for generating a quantum bit drive signal according to claim 16, wherein: When the first microwave signal and the second microwave signal correspond to the same qubit drive signal, determining the frequency difference between the two microwave signals includes: Determine a frequency difference between two first microwave signals of different frequencies; wherein the two first microwave signals correspond to qubit drive signals of different frequencies, respectively.

19. The method for generating a quantum bit drive signal according to claim 18, wherein: When the first microwave signal and the second microwave signal correspond to the same qubit drive signal, determining the frequency difference between the two microwave signals further includes: Two second microwave signals are determined based on a frequency difference between the two first microwave signals; wherein the frequency difference between the two second microwave signals is an integer multiple of the frequency difference between the two first microwave signals.

20. The method for generating a quantum bit drive signal according to claim 16, wherein: The generating the trigger signal based on the trigger period includes: The trigger signal is generated at a time that is an integer multiple of the trigger period.

21. The method for generating a qubit drive signal according to claim 15, wherein: The determining of a phase coherence point based on the phases of the two microwave signals and generating a trigger signal according to the phase coherence point includes: determining a phase difference between the first microwave signal and the second microwave signal at the same moment as a preset phase difference; obtaining a current phase difference between the first microwave signal and the second microwave signal; The moment when the current phase difference is the same as the preset phase difference is determined as the phase coherence point, and the trigger signal is output at the phase coherence point.

22. The method for generating a qubit drive signal according to claim 15, wherein: The determining of a phase coherence point based on the phases of the two microwave signals and generating a trigger signal according to the phase coherence point includes: Determining a preset phase difference according to a difference between a first phase difference of the two first microwave signals and a second phase difference of the two second microwave signals at the same time; Obtaining a current first phase difference between the two first microwave signals and a current second phase difference between the two second microwave signals; The moment when the difference between the current first phase difference and the current second phase difference is the same as the preset phase difference is determined as the phase coherence point, and the trigger signal is output at the phase coherence point.

23. A quantum computer, characterized in that A device for generating a qubit drive signal comprising the device of any one of claims 1 to 13, or a method for generating a qubit drive signal using the method of any one of claims 14 to 22 for generating a qubit drive signal for controlling the quantum state information of a qubit on a quantum chip.

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