Qubit measurement device, quantum measurement system, and quantum computer

Abstract

A qubit measurement device, a quantum measurement system, and a quantum computer. The present application discloses a qubit measurement device, comprising: a plurality of first clock modules, each of which is configured to distribute a plurality of mutually synchronized working clock signals according to a received clock source signal and a second pulse signal; wherein the second pulse signal is used to align a plurality of working clock signals; a signal output module configured to receive task data and a trigger signal and output a plurality of measurement signals for measuring quantum state information of a qubit on a quantum processor according to the working clock signal; a signal acquisition module configured to receive the task data and the trigger signal and process a reflection signal corresponding to the measurement signal according to the working clock signal; wherein the reflection signal is a signal carrying the operation result after the qubit performs the operation; wherein the signal output module and the signal acquisition module are in communication connection. The present application improves the measurement accuracy of the operation result of the qubit.

Description

Technical Field

[0001] This application belongs to the quantum field, and in particular to a qubit measurement device, a quantum measurement system, and a quantum computer. Background Technology

[0002] A quantum processor is the computational execution unit in quantum computing, composed of qubits. To ensure the operation of the qubits and the data of their results, various driving signals need to be provided to the qubits, and the results of their operation need to be measured. In the quantum realm, especially in superconducting quantum computing, indirect measurement methods are commonly used to measure qubits. Specifically, a resonant cavity is used to couple the qubits, and the resonant cavity and qubits interact with each other; the state changes of the qubits are obtained by measuring the state changes of the resonant cavity. When testing the resonant cavity, a reflection mode is usually used, that is, a measurement signal is applied to the resonant cavity, the reflected signal is collected, and processed to obtain the state information of the qubits.

[0003] In existing technologies, various commercial instruments are typically used to build quantum measurement and control systems. For example, arbitrary waveform generators and microwave sources are used as signal source modules to output measurement signals, which are then acquired and processed by instruments such as signal analyzers. Since qubits have a short decoherence time, qubit measurements must be completed within this time. Furthermore, the application of the measurement signal and the acquisition of the reflected signal must be synchronized to ensure the accuracy of the quantum state information of the qubit obtained after processing.

[0004] The existing quantum measurement and control systems all use commercial instruments, making it difficult to guarantee the clock synchronization accuracy between instruments. Moreover, with the development of quantum technology, the number of qubits integrated on quantum processors is increasing, and the number of signal source modules and signal acquisition modules required in the corresponding quantum measurement and control systems is also increasing. This makes it even more difficult to accurately synchronize the clocks between multiple signal source modules and signal acquisition modules, resulting in large measurement errors.

[0005] Therefore, how to improve the clock synchronization of the signal source module and the signal acquisition module in a quantum measurement and control system has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this application is to provide a qubit measurement device, a quantum measurement system, and a quantum computer, which improves the measurement accuracy of qubit operation results.

[0007] The specific technical solution of this application is as follows:

[0008] One aspect of this application provides a qubit measurement device, comprising:

[0009] A plurality of first clock modules, each first clock module being configured to distribute a plurality of mutually synchronized working clock signals based on a received clock source signal and a second pulse signal; wherein the second pulse signal is used to align the plurality of working clock signals;

[0010] The signal output module is configured to receive task data and trigger signals and output multiple measurement signals for measuring the quantum state information of qubits on the quantum processor according to the working clock signal;

[0011] A signal acquisition module is configured to receive the task data and a trigger signal and process the reflected signal corresponding to the measurement signal according to the working clock signal; wherein the reflected signal is a signal carrying the operation result after the qubit performs the operation;

[0012] The signal output module is communicatively connected to the signal acquisition module.

[0013] The quantum bit measurement device described above, preferably, further includes a board body, on which multiple first clock modules, the signal output module, and the signal acquisition module are integrated.

[0014] In the quantum bit measurement device described above, preferably, the signal output module includes:

[0015] A first control unit is configured to receive the task data and trigger signal and forward the task data and trigger signal according to the working clock signal;

[0016] Multiple signal output units are configured to receive the task data and trigger signal and output multiple measurement signals for measuring the quantum state information of qubits on the quantum processor according to the working clock signal.

[0017] In the quantum bit measurement device described above, preferably, the first control unit includes an FPGA, MCU, MPU, or DSP.

[0018] In the quantum bit measurement device described above, preferably, the signal output unit includes a DAC.

[0019] The quantum bit measurement device described above preferably further includes a second clock module configured to output a clock signal for configuring the first control unit.

[0020] In the quantum bit measurement device described above, preferably, the signal acquisition module includes:

[0021] The second control unit is configured to receive the task data and trigger signal and forward the task data and trigger signal according to the working clock signal;

[0022] Multiple signal acquisition units are configured to receive the task data and trigger signal and process the reflected signal corresponding to the measurement signal according to the working clock signal.

[0023] In the quantum bit measurement device described above, preferably, the second control unit includes an FPGA, MCU, MPU, or DSP.

[0024] In the quantum bit measurement device described above, preferably, the signal acquisition unit includes an ADC.

[0025] The quantum bit measurement device described above preferably further includes a third clock module configured to output a clock signal for configuring the second control unit.

[0026] The quantum bit measurement device described above preferably further includes multiple memories, each of which is communicatively connected to the signal output module or the signal acquisition module for storing the task data.

[0027] The qubit measurement device described above preferably further includes a fourth clock module configured to output a clock signal for the operation of the memory.

[0028] The quantum bit measurement device described above preferably further includes a power supply module, which provides power signals to the first clock module, the signal output module, and the signal acquisition module.

[0029] In another aspect, this application provides a quantum measurement system, including a backplane and a plurality of qubit measurement devices as described in any one of the preceding claims, wherein the plurality of qubit measurement devices are integrated on the backplane.

[0030] In another aspect, this application provides a quantum computer system, including the aforementioned quantum measurement system and quantum processor, wherein the quantum measurement system is configured to measure the computational results of the quantum processor.

[0031] Compared with the prior art, this application has the following beneficial effects:

[0032] This application provides a qubit measurement device, comprising: a plurality of first clock modules, each first clock module being configured to distribute a plurality of mutually synchronized working clock signals based on a received clock source signal and a second pulse signal, wherein the second pulse signal is used to align the plurality of working clock signals; a signal output module, configured to receive task data and a trigger signal and output multiple measurement signals for measuring the quantum state information of qubits on a quantum processor based on the working clock signals; and a signal acquisition module, configured to receive the task data and the trigger signal and process reflected signals corresponding to the measurement signals based on the working clock signals; wherein the reflected signals are signals carrying the operation results after the qubits perform operations, and the signal output module is communicatively connected to the signal acquisition module. This application receives a clock source signal through a first clock module and divides it into multiple working clock signals to ensure that the multiple working clock signals are from the same source. It also uses a second pulse signal to align the multiple working clock signals, ensuring that the synchronization accuracy of the working clock signals distributed to the signal output module and the signal acquisition module is very high. Furthermore, the signal output module and the signal acquisition module are connected in communication to ensure the synchronization accuracy of the clock and trigger for outputting measurement signals and processing reflected signals, thereby improving the measurement accuracy of the quantum processor. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a quantum processor circuit structure provided in an embodiment of this application;

[0034] Figure 2 A schematic diagram of a quantum measurement and control system built with prior art is provided for the embodiments of this application;

[0035] Figure 3 A schematic diagram of a qubit measurement device provided in this application embodiment. Figure 1 ;

[0036] Figure 4 A schematic diagram of a qubit measurement device provided in this application embodiment. Figure 2 ;

[0037] Figure 5 This is a schematic diagram of a quantum measurement system provided in an embodiment of this application.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1 – First clock module, 2 – Signal output module, 3 – Signal acquisition module, 4 – Second clock module, 5 – Third clock module, 6 – Memory, 7 – Fourth clock module

[0040] 21 - First control unit, 22 - Signal output unit, 31 - Second control unit, 32 - Signal acquisition unit. Detailed Implementation

[0041] The following detailed description is illustrative only and is not intended to limit the embodiments and / or their application or use. Furthermore, it is not intended to be construed as being bound by any express or implied information presented in the preceding "Background Art" or "Summary of the Invention" or "Detailed Description" sections.

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, one or more embodiments are now described with reference to the accompanying drawings, wherein similar reference numerals are used throughout the text to refer to similar components. In the following description, numerous specific details are set forth for purposes of explanation in order to provide a more thorough understanding of one or more embodiments. However, it will be apparent that one or more embodiments may be practiced in various circumstances without these specific details, and the various embodiments may be combined with and referenced to each other without contradiction.

[0043] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0044] like Figure 1 The quantum processor shown includes multiple one-to-one corresponding and mutually coupled qubits and resonant cavities. The end of each resonant cavity furthest from the corresponding qubit is connected to a measurement bus. The input end of the measurement bus is used to apply a measurement signal, and the output end of the measurement bus is used to collect the reflected signal corresponding to the measurement signal. The state information of the multiple qubits to be measured is obtained by processing and analyzing the reflected signal, and then the operation result of the qubit is obtained.

[0045] like Figure 2The prior art shown depicts a quantum measurement and control system built using commercial instruments. As is well known, a quantum processor has multiple qubits, and quantum computing tasks can be performed by a single qubit or by multiple qubits working together. To ensure the normal operation of each qubit, various driving signals are needed, such as frequency driving signals to drive single or multiple qubits to perform gate operations. Specifically, this includes single-qubit gate frequency driving signals, provided by a DC signal source, and multi-qubit gate frequency driving signals, provided by a pulse signal source. Furthermore, when a qubit performs quantum computation, it needs to be modulated to a target quantum state, specifically through a microwave signal source outputting quantum state driving signals. After the quantum processor completes the quantum computation, the computation results need to be measured and processed using signal acquisition and processing equipment to obtain the final result.

[0046] Multiple signal acquisition and processing devices are typically independent commercial instruments. However, when the number of qubits on a quantum processor is very large, multiple signal acquisition and processing devices need to work together for measurement and processing. Furthermore, in the qubit measurement process, applying the measurement signal to one end of the measurement bus and acquiring and processing the corresponding reflected signal from the other end of the measurement bus need to be performed synchronously to ensure the accuracy of the measurement results. When multiple independent commercial signal sources are used to collaboratively measure qubits, clock errors exist between the signal sources, making it difficult to guarantee the synchronization of the output measurement signal and the processed reflected signal, directly affecting the measurement accuracy of the quantum processor.

[0047] like Figure 3 As shown, an embodiment of this application provides a qubit measurement device, including: a plurality of first clock modules 1, each first clock module 1 being configured to distribute a plurality of mutually synchronized working clock signals based on a received clock source signal and a second pulse signal, wherein the second pulse is used to align the plurality of working clock signals; a signal output module 2, configured to receive task data and a trigger signal and output multiple measurement signals for measuring the quantum state information of qubits on a quantum processor based on the working clock signals; and a signal acquisition module 3, configured to receive the task data and the trigger signal and process the reflected signal corresponding to the measurement signal based on the working clock signal; wherein the reflected signal is a signal carrying the operation result after the qubit performs an operation; wherein the signal output module 2 and the signal acquisition module 3 are communicatively connected.

[0048] Specifically, signal output module 2 and signal acquisition module 3 are two independent functional modules. Signal output module 2 outputs measurement signals based on task data and trigger signals, while signal acquisition module 3 acquires reflected signals based on task data and trigger signals, processes and analyzes them to obtain calculation results. Multiple first clock modules 1 are used, each of which distributes multiple synchronized working clock signals to signal output module 2 or signal acquisition module 3 based on the received clock source signal and second pulse signal. It can be understood that one first clock module 1 is responsible for providing multiple synchronized working clock signals to one signal output module 2 or signal acquisition module 3. Therefore, the working clock signals of signal output module 2 and signal acquisition module 3 are provided by two first clock modules 1. The signal output module 2 and signal acquisition module 3 are communicatively connected to ensure that they can communicate with each other. Synchronization is achieved through mutual communication, such as synchronization of working clock signals and trigger signals, ensuring the accuracy of measurement results when signal output module 2 and signal acquisition module 3 collaboratively perform qubit measurement.

[0049] This application receives a clock source signal through a first clock module 1 and divides it into multiple working clock signals to ensure that the multiple working clock signals are from the same source. It also uses a second pulse signal to align the multiple working clock signals, ensuring that the synchronization accuracy of the working clock signals distributed to the signal output module 2 and the signal acquisition module 3 is very high. Furthermore, the signal output module 2 and the signal acquisition module 3 are connected through a communication link to further ensure the synchronization accuracy of the clock and trigger of the output measurement signal and the processing of the reflected signal, thereby improving the measurement accuracy of the quantum processor.

[0050] In one embodiment of this application, the qubit measurement device further includes a board body, on which multiple first clock modules 1, signal output modules 2, and signal acquisition modules 3 are integrated. Specifically, the multiple first clock modules 1, signal output modules 2, and signal acquisition modules 3 are all integrated circuits. By using a board body to integrate all functional modules onto a single board, the device achieves small size, high integration, and easy expansion.

[0051] In one embodiment of this application, the signal output module 2 includes: a first control unit 21 configured to receive the task data and a trigger signal and forward the task data and trigger signal according to the working clock signal; and a plurality of signal output units 22 configured to receive the task data and the trigger signal and output multiple measurement signals for measuring the quantum state information of qubits on the quantum processor according to the working clock signal. The signal output units 22 are used to generate measurement signals based on the task data and output measurement signals according to the trigger signal and the working clock signal. To achieve the measurement of multiple qubits, multiple signal output units 22 are correspondingly set, and the first control unit 21 controls the multiple signal output units 22 through the trigger signal and the working clock signal to ensure that the multiple signal output units 22 output multiple synchronous measurement signals, facilitating the simultaneous measurement of multiple qubits.

[0052] In one embodiment of this application, the first control unit 21 includes an FPGA, MCU, MPU, or DSP. The first control unit 21 is a device with data forwarding and processing functions, and can generally be an FPGA (Field Programmable Gate Array), MCU (Microcontroller Unit), MPU (Microprocessor Unit), or DSP (Digital Signal Processor). In this embodiment, the first control unit 21 is preferably an FPGA; in other embodiments, other devices with similar data processing functions may be used, and no limitation is made here.

[0053] In one embodiment of this application, the signal output unit 22 includes a DAC. The signal output unit 22 is a device that outputs pulse signals based on task data, and a DAC (Digital to Analog Converter) can generally be selected. In this embodiment, the pulse signal is used to measure the sinusoidal signal of the quantum state of the qubit. The parameters such as the pulse amplitude, pulse width, and phase of the sinusoidal signal are adjusted. Therefore, in this example, a DAC with a sampling rate of approximately 3 GHz is preferred as the signal output unit 22 to ensure high accuracy of the output pulse signal, thereby improving the measurement accuracy of the qubit computation results.

[0054] As one embodiment of this application, the qubit measurement device further includes a second clock module 4, which is configured to output a clock signal for configuring the first control unit 21. Before the first control unit 21 operates, its built-in parameters, such as the clock signal, also need to be configured. The second clock module 4 configures the built-in clock parameters of the first control unit 21 to ensure its normal operation.

[0055] In one embodiment of this application, the signal acquisition module 3 includes: a second control unit 31 configured to receive the task data and trigger signal and forward the task data and trigger signal according to a working clock signal; and multiple signal acquisition units 32 configured to receive the task data and trigger signal and process the reflected signal corresponding to the measurement signal according to the working clock signal. The signal acquisition units 32 are used to acquire the reflected signal according to the task data and working clock signal, and process and analyze the acquired reflected signal according to the trigger signal to obtain the corresponding calculation result. To achieve the acquisition of reflected signals output by multiple qubits, multiple signal acquisition units 32 are set up, and the second control unit 31 controls the multiple signal acquisition units 32 through trigger signal and working clock signal to ensure that the multiple signal acquisition units 32 synchronously acquire the reflected signal output by the qubits, facilitating simultaneous measurement of multiple qubits.

[0056] It should be noted that the first control unit 21 in the signal output module 2 is communicatively connected to the second control unit 31 in the signal acquisition module 3. Through mutual communication, the working clock signal and the trigger signal are synchronized, thereby improving the accuracy of the measurement results when the signal output unit 22 and the signal acquisition unit 32 work together to measure the qubit.

[0057] Specifically, the first control unit 21 and the second control unit 31 are connected via an LVDS interface, which provides stable communication performance and high information transmission rate, facilitating accurate acquisition of configuration information and operating status, and ensuring the stable performance of the entire quantum state drive signal generator. The first control unit 21 and the second control unit 31 synchronize their working clock signal and trigger signal according to the LVDS protocol to ensure synchronization between the signal output unit 22 and the signal acquisition unit 32.

[0058] In one embodiment of this application, the second control unit 31 includes an FPGA, MCU, MPU, or DSP. The second control unit 31 is a device with data forwarding and processing functions, and can generally be an FPGA (Field Programmable Gate Array), MCU (Microcontroller Unit), MPU (Microprocessor Unit), or DSP (Digital Signal Processor). In this embodiment, the second control unit 31 is preferably an FPGA; in other embodiments, other devices with similar data processing functions may be used, and no limitation is made here.

[0059] In one embodiment of this application, the signal acquisition unit 32 includes an ADC. The signal acquisition unit 32 is a device for acquiring the reflected signal output by the quantum processor. The reflected signal is typically an analog signal carrying the result of qubit operations, and an ADC (Attack Damage Carry / Core) can generally be selected. In this embodiment, an ADC with a sampling rate of approximately 3 GHz is chosen as the signal acquisition unit 32 to ensure the accuracy of the output pulse signal, thereby improving the measurement accuracy of the qubits.

[0060] As one embodiment of this application, the qubit measurement device further includes a third clock module 5, which is configured to output a clock signal for configuring the second control unit 31. Before operation, the second control unit 31 also needs to have its built-in parameters configured, such as the clock signal. The third clock module 5 configures the built-in clock parameters of the second control unit 31 to ensure its normal operation.

[0061] In one embodiment of this application, the qubit measurement device further includes multiple memories 6, each of which is communicatively connected to the signal output module 2 or the signal acquisition module 3, for storing the task data. The task data specifically includes signal waveform parameters and signal waveform timing of the measurement signal. Specifically, the signal waveform parameters are the waveform parameters of the pulse signal output by the signal output unit 22, such as pulse amplitude, pulse width, and ringing amplitude. The signal waveform timing refers to the application time of the pulse signal. When the quantum processor executes a quantum computing task, the multiple driving signals applied to the qubit have a time sequence, and the measurement of the qubit also has a time sequence. The measurement signals must be applied strictly according to the preset time sequence, and the reflected signals must be acquired to ensure the measurement accuracy of the qubit. Therefore, for quantum computing tasks, not only is the memory occupied by the task data usually large, but the memory occupied by the computational results obtained after processing the acquired reflected signals is also very large. Memory 6 is needed for storage to save memory consumption of the signal output module 2 and the signal acquisition module 3. In this embodiment, the memory 6 is preferably DDR, and there can be multiple DDRs.

[0062] In one embodiment of this application, the qubit measurement device further includes a fourth clock module 7, which is configured to output a clock signal for the operation of the memory 6. Specifically, the fourth clock module 7 may include a crystal oscillator and is connected to the memory 6 via a phase-locked loop circuit to provide a stable high-frequency clock signal for the memory 6.

[0063] In one embodiment of this application, the qubit measurement device further includes a power supply module, which provides power signals to the first clock module 1, the signal output module 2, and the signal acquisition module 3. The first clock module 1, the signal output module 2, and the signal acquisition module 3 are all active devices, and the power supply module provides power signals for the operation of other functional modules.

[0064] As one embodiment of this application, the quantum state driving signal generator further includes several signal connectors, each of which is configured to receive the clock source signal and / or the second pulse signal, output a measurement signal and / or acquire a transmission signal, facilitating cable connection and disconnection. In this embodiment, the signal connectors are preferably SSMA RF connectors, which are small in size, have a simple structure, and stable performance.

[0065] Based on the same concept, embodiments of this application also provide a quantum measurement system, including a backplane and a plurality of qubit measurement devices as described above, wherein the plurality of qubit measurement devices are integrated on the backplane. The functional modules of the qubit measurement devices can be integrated into a single board body; and multiple board bodies can be integrated into a single backplane, allowing for the integration of multiple qubit measurement devices on a single backplane, facilitating expansion and enabling the measurement of quantum processors with more qubits.

[0066] Based on the same concept, embodiments of this application also provide a quantum computer system, including the aforementioned quantum measurement system and quantum processor, wherein the quantum measurement system is configured to measure the computational results of the quantum processor.

[0067] The above description, based on the embodiments shown in the drawings, details the structure, features, and effects of this application. The above description is only a preferred embodiment of this application, but this application does not limit the scope of implementation to what is shown in the drawings. Any changes made in accordance with the concept of this application, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and drawings, should be within the protection scope of this application.

Claims

1. A qubit measurement device, characterized by, include: A plurality of first clock modules, each first clock module being configured to distribute a plurality of mutually synchronized working clock signals based on a received clock source signal and a second pulse signal; wherein the second pulse signal is used to align the plurality of working clock signals; The signal output module includes a first control unit and multiple signal output units. The first control unit is configured to receive task data and trigger signals and forward the task data and trigger signals according to the working clock signal. The multiple signal output units are configured to receive the task data and trigger signals and output multiple measurement signals for measuring the quantum state information of qubits on the quantum processor according to the working clock signal. A second clock module is configured to output a clock signal for configuring the first control unit; The signal acquisition module includes a second control unit and multiple signal acquisition units. The second control unit is configured to receive the task data and trigger signal and forward the task data and trigger signal according to a working clock signal. The multiple signal acquisition units are configured to receive the task data and trigger signal and process the reflected signal corresponding to the measurement signal according to the working clock signal. The reflected signal is a signal carrying the operation result after the qubit performs the operation. A third clock module is configured to output a clock signal for configuring the second control unit; The first control unit is communicatively connected to the second control unit.

2. The qubit measurement device of claim 1, wherein, It also includes a main board body, on which multiple first clock modules, signal output modules and signal acquisition modules are integrated.

3. The qubit measurement device of claim 1, wherein, The first control unit includes an FPGA, MCU, MPU, or DSP.

4. The qubit measurement device of claim 1, wherein, The signal output unit includes a DAC.

5. The qubit measurement device of claim 1, wherein, The second control unit includes an FPGA, MCU, MPU, or DSP.

6. The qubit measurement device of claim 1, wherein, The signal acquisition unit includes an ADC.

7. The qubit measurement device of claim 1, wherein, It also includes multiple memories, each of which is communicatively connected to the signal output module or the signal acquisition module, for storing the task data.

8. The qubit measurement device of claim 7, wherein, It also includes a fourth clock module, which is configured to output a clock signal for the operation of the memory.

9. The qubit measurement device of claim 1, wherein, It also includes a power module, which provides power signals to the first clock module, the signal output module, and the signal acquisition module.

10. A quantum measurement system, characterized by, It includes a backplate and a plurality of qubit measurement devices as described in any one of claims 1-9, wherein the plurality of qubit measurement devices are integrated on the backplate.

11. A quantum computer system, characterized by, The invention includes the quantum measurement system and quantum processor of claim 10, wherein the quantum measurement system is configured to measure the computational results of the quantum processor.

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