Quantum measurement and control system, quantum computer, system and network and communication method

Abstract

The present invention discloses a quantum measurement and control system, a quantum computer, a system, a network and a communication method. The quantum measurement and control system includes: at least one arbitrary waveform generator and at least one quantum analyzer, wherein the arbitrary waveform generator is used to receive the waveform control parameters transmitted from the host computer, generate the required arbitrary wave data according to the waveform control parameters, perform digital-to-analog conversion on the arbitrary wave data, generate the corresponding analog signal and transmit it to the quantum chip; and / or the quantum analyzer is used to collect the radio frequency analog signal of the quantum chip, perform analog-to-digital conversion on the collected radio frequency analog signal to obtain the corresponding digital signal, extract the amplitude and phase data of the preset frequency point in the spectrum corresponding to the digital signal, and transmit the extracted amplitude and phase data to the host computer. The present invention greatly reduces the data interaction between the quantum measurement and control system and the host computer, reduces the requirements for the performance of the host computer, and realizes the acceleration function of quantum bit measurement and control.

Description

Technical Field

[0001] The present invention relates to a quantum measurement and control system, a quantum computer, a system and a network and a communication method. Background Art

[0002] In the current superconducting quantum measurement and control system, users interact with the quantum measurement and control system through an independent host computer through a gigabit network port switch, and transmit the arbitrary waveform required to be emitted to the arbitrary waveform generator in the quantum measurement and control system through the host computer. The quantum analyzer in the quantum measurement and control system sends the collected signal to the host computer for analysis and processing to obtain the current state of the quantum bit. A typical example, assuming that the sampling rate of the digital to analog converter (DAC) chip in the arbitrary waveform generator and the analog to digital converter (ADC) chip in the quantum analyzer are both 2Gsa / s, then emitting a 100ns waveform requires transmitting 200 points of data, and collecting a 5us waveform requires transmitting 10,000 points of data.

[0003] During the bit parameter calibration stage of superconducting quantum computing and the actual execution of quantum computing algorithms, various forms of pulse waveforms need to be emitted, which may be a special waveform with a longer time or many short pulse waveforms. At the same time, each set of experiments requires waveform acquisition and data analysis of the bit state. Some simple and basic quantum computing experiments, such as scanning of cavity frequency and energy spectrum, require the emission of pulse waveforms under different conditions and the corresponding acquisition of RF signals, and then sending the acquired signals to the host computer for data analysis to complete the scanning of cavity frequency and energy spectrum. Summary of the invention

[0004] The inventor of the present invention has found that in the process of superconducting quantum measurement and control, due to the huge amount of data transmission between the quantum measurement and control system and the host computer, it takes a long time, making the efficiency of this communication method low. Some solutions have also been proposed in the prior art, such as using a backplane or an optical port switch to connect the computer host module, the arbitrary waveform generator module and the quantum analyzer (data acquisition module) in the system. These solutions can increase the data transmission efficiency by 10 to 100 times. However, compared with the gigabit network port switch, the backplane's sub-board bearing, high-speed signal transmission and power transmission functions make the backplane layer number, thickness, number of through holes, reliability requirements, frequency and high-speed signal transmission quality and other aspects very high. The optical module used in the optical port has relatively harsh use conditions, high hardware cost and transmission efficiency will still encounter the bottleneck of the host computer calculation and storage speed, so the technical difficulty of such solutions is greatly increased, the cost is also greatly increased, and it is heavily dependent on hardware, which is not conducive to the expansion of quantum bit measurement and control.

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

[0006] In a first aspect, an embodiment of the present invention provides a quantum measurement and control system, comprising: at least one arbitrary waveform generator and at least one quantum analyzer, wherein the arbitrary waveform generator is used to receive waveform control parameters transmitted from a host computer, generate required arbitrary wave data according to the waveform control parameters, perform digital-to-analog conversion on the arbitrary wave data, generate corresponding analog signals and transmit them to a quantum chip to manipulate quantum bits; and / or

[0007] The quantum analyzer is used to collect the radio frequency analog signal of the quantum chip, perform analog-to-digital conversion on the collected radio frequency analog signal to obtain a corresponding digital signal, extract the amplitude and phase data of a preset frequency point in the spectrum corresponding to the digital signal, and transmit the extracted amplitude and phase data to the host computer.

[0008] In one embodiment, the arbitrary waveform generator includes: a first programmable logic device and a digital-to-analog converter electrically connected to the first programmable logic device;

[0009] The first programmable logic device includes a memory, wherein the memory stores waveform data of a preset period;

[0010] The first programmable logic device is used to sample the waveform data storing the preset period according to the preset sampling frequency to obtain the vertical resolution data of the sampling point, calculate and process the vertical resolution data of the sampling point according to the waveform control parameter, obtain the required arbitrary wave data, and send it to the digital-to-analog converter;

[0011] The digital-to-analog converter is used to perform digital-to-analog conversion on the arbitrary wave data, generate a corresponding analog signal and output it.

[0012] In one embodiment, the required arbitrary wave data is a Gaussian modulated sine wave;

[0013] The first programmable logic device includes a memory, wherein the memory stores sine wave data and Gaussian wave data of a preset period;

[0014] The first programmable logic device is used to calculate the sine wave data and Gaussian wave data selected at each sampling moment according to the input waveform control parameters, multiply the calculation results to obtain Gaussian modulated sine wave data, and transmit the amplitude information of the Gaussian modulated sine wave to the digital-to-analog converter.

[0015] In one embodiment, the quantum analyzer includes: a second programmable logic device and an analog-to-digital converter electrically connected to the second programmable logic device;

[0016] The analog-to-digital converter is specifically used to collect the radio frequency analog signal obtained by monitoring the state of the quantum bit in the quantum chip each time, and perform analog-to-digital conversion on the radio frequency analog signal to obtain and output the corresponding digital signal;

[0017] The second programmable logic device is used to extract a preset number of data points containing bit information from the digital signal output by the analog-to-digital converter, perform fast Fourier transform, obtain corresponding spectrum data, determine the frequency points corresponding to the data points from the spectrum data, and extract the amplitude and phase data corresponding to the frequency points based on the frequency points, and transmit the extracted amplitude and phase data to the host computer.

[0018] In one embodiment, the arbitrary waveform generator further includes: a first network port, the first network port is electrically connected to the first programmable logic device, and is used to connect to a switch outside the quantum measurement and control system, receive the waveform control parameter from the switch and output it to the first programmable logic device;

[0019] The quantum analyzer also includes: a second network port, which is electrically connected to the second programmable logic device and is used to connect to a switch outside the quantum measurement and control system, receive the amplitude and phase data from the second programmable logic device, and transmit it to the host computer through the switch.

[0020] In one embodiment, the arbitrary waveform generator and the quantum analyzer are respectively arranged on different boards; or

[0021] The arbitrary waveform generator and the quantum analyzer are arranged on the same board.

[0022] In one embodiment, the arbitrary waveform generator and the quantum analyzer are arranged on the same board, and the first programmable logic device and the second programmable logic device are integrated into the same field programmable gate array.

[0023] In a second aspect, an embodiment of the present invention provides a quantum computer, comprising the aforementioned quantum measurement and control system and quantum chip.

[0024] In a third aspect, an embodiment of the present invention provides a quantum computing system, including: a host computer, a quantum measurement and control system, and a quantum chip; the host computer and the quantum measurement and control system are communicatively connected; wherein:

[0025] The host computer is used to send waveform control parameters to the quantum measurement and control system, and obtain amplitude and phase data from the quantum measurement and control system, and analyze the probability that the quantum bit in the quantum chip is in a preset quantum state according to the amplitude and phase data;

[0026] The quantum measurement and control system includes: an arbitrary waveform generator and a quantum analyzer, wherein: the arbitrary waveform generator is used to receive waveform control parameters transmitted from a host computer, generate required arbitrary wave data according to the waveform control parameters, perform digital-to-analog conversion on the arbitrary wave data, generate corresponding analog signals and transmit them to the quantum chip; and / or the quantum analyzer is used to collect radio frequency analog signals from the quantum chip, perform analog-to-digital conversion on the collected radio frequency analog signals to obtain corresponding digital signals, extract amplitude and phase data of preset frequency points in the frequency spectrum corresponding to the digital signal, and transmit the extracted amplitude and phase data to the host computer.

[0027] In one embodiment, the quantum computing system further includes:

[0028] A switch is respectively communicatively connected with the host computer and the quantum measurement and control system.

[0029] In a fourth aspect, an embodiment of the present invention provides a quantum communication network, wherein the quantum communication network includes at least one quantum computing system as described above.

[0030] In a fifth aspect, an embodiment of the present invention provides a method for performing quantum communication using the aforementioned quantum computing system.

[0031] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0032] The above-mentioned quantum measurement and control system provided by the embodiment of the present invention realizes the execution of distributed edge computing by using an arbitrary waveform generator board and a quantum analyzer without increasing the hardware cost, and the waveform generation operation and the analysis and processing operation of the collected waveform are completed on the side close to the superconducting quantum bit (the arbitrary waveform generator and the quantum analyzer side), which greatly reduces the data interaction between the quantum measurement and control system and the host computer, improves the efficiency of quantum measurement and control, and reduces the requirements for the performance of the host computer. The quantum measurement and control system is used to realize the acceleration function of quantum bit measurement and control.

[0033] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0034] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0036] Figure 1 This is one of the structural schematic diagrams of the quantum measurement and control system in an embodiment of the present invention;

[0037] Figure 2 This is the second structural diagram of the quantum measurement and control system in an embodiment of the present invention;

[0038] Figure 3 A schematic diagram of data transmission for generating an arbitrary waveform according to the present invention in a specific example;

[0039] Figure 4 A schematic diagram of data transmission for generating an arbitrary waveform according to an existing implementation method in a specific example;

[0040] Figure 5 A schematic diagram of data transmission for data collection and analysis according to an existing implementation method in a specific example;

[0041] Figure 6 It is a data transmission diagram for performing data collection and analysis according to the method of the present invention in a specific example. DETAILED DESCRIPTION

[0042] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0043] The specific implementation methods of the quantum measurement and control system, quantum computer, system, network and communication method provided in the embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0044] The quantum measurement and control system provided by the embodiment of the present invention refers to Figure 1 As shown, it includes: at least one arbitrary waveform generator 1 and at least one quantum analyzer 2, wherein the arbitrary waveform generator 1 is used to receive waveform control parameters transmitted from the host computer, generate required arbitrary wave data according to the waveform control parameters, perform digital-to-analog conversion on the arbitrary wave data, generate corresponding analog signals and transmit them to the quantum chip so as to manipulate the quantum bits; and / or

[0045] The quantum analyzer 2 is used to collect the radio frequency analog signal of the quantum chip, perform analog-to-digital conversion on the collected radio frequency analog signal to obtain the corresponding digital signal, extract the amplitude and phase data of the preset frequency point in the spectrum corresponding to the digital signal, and transmit the extracted amplitude and phase data to the host computer so that the host computer can analyze the probability that the quantum bit in the quantum chip is in a preset quantum state.

[0046] The above-mentioned quantum measurement and control system provided by the embodiment of the present invention realizes the execution of distributed edge computing by using an arbitrary waveform generator board and a quantum analyzer without increasing the hardware cost, and the waveform generation operation and the analysis and processing operation of the collected waveform are completed on the side close to the superconducting quantum bit (the arbitrary waveform generator 1 and the quantum analyzer 2 side), which greatly reduces the data interaction between the quantum measurement and control system and the host computer, and at the same time reduces the requirements for the performance of the host computer, and realizes the acceleration function of the measurement and control of the quantum bit by using the quantum measurement and control system.

[0047] In the above-mentioned quantum measurement and control system provided by the embodiment of the present invention, there can be multiple arbitrary waveform generators 1 and quantum analyzers 2. Multiple arbitrary waveform generators 1 and quantum analyzers 2 can communicate with the host computer through the network. Each arbitrary waveform generator 1 serves as a channel. According to the practice in the prior art, the host computer needs to prepare waveform data for a large number of arbitrary waveform generators 1, and all of them are calculated by the host computer CPU at one time according to the parameters input by the user, and then sent to each arbitrary waveform generator in turn through the network port of the host computer. The data that the host computer needs to process is huge, and the transmission efficiency is limited by the network transmission capacity. The embodiment of the present invention is based on the idea of ​​edge computing in cloud computing, that is, it refers to an open platform integrating network, computing, storage, and application core capabilities on the side close to the source of objects or data, and provides the nearest service nearby. Edge computing can greatly reduce the impact on applications at cloud center mode sites. The information processing of edge computing is located near the edge, that is, where things and people generate or use the information. In the embodiment of the present invention, the work of generating arbitrary waveform data is performed in the arbitrary waveform generator, and the host computer is responsible for transmitting the waveform control parameters, which greatly reduces the data communicated between the host computer and the quantum measurement and control system, thereby improving the efficiency of signal transmission and reducing the requirements on the processing capability of the host computer.

[0048] The situation of quantum analyzers is similar to this. According to the practice in the prior art, the RF analog signals collected by each quantum analyzer are converted into digital signals and then transmitted to the host computer for analysis and processing. The host computer segments the data transmitted by a large number of quantum analyzers and then performs corresponding time domain to frequency domain processing, extracts the amplitude and phase and analyzes them. Not only is the amount of data transmitted huge, but it also tests the processing power of the CPU of the host computer. In the embodiment of the present invention, the data processing and extraction operations are transferred to the quantum analyzer. The host computer is responsible for analyzing the probability of the quantum bit in the preset quantum state based on the amplitude and phase data, which also reduces the data communicated between the host computer and the quantum measurement and control system, improves the efficiency of signal transmission, and reduces the requirements for the processing power of the host computer.

[0049] In the above-mentioned quantum measurement and control system, both the arbitrary waveform generator 1 and the quantum analyzer 2 adopt the above-mentioned improved solution provided by the embodiment of the present invention; or, the arbitrary waveform generator 1 can adopt the improved solution provided by the embodiment of the present invention, while the quantum analyzer 2 adopts the solution of the prior art; or, the arbitrary waveform generator 1 adopts the implementation solution in the prior art, while the quantum analyzer 2 adopts the improved solution provided by the embodiment of the present invention.

[0050] In order to realize the above-mentioned acceleration function of quantum bit measurement and control, the embodiment of the present invention adopts hardware acceleration, that is, the work with very large computational amount is assigned to special hardware for processing to reduce the workload of the central processing unit.

[0051] In one embodiment, referring to Figure 2 As shown, the arbitrary waveform generator in the above quantum measurement and control system provided by the embodiment of the present invention includes: a first programmable logic device and a digital-to-analog converter electrically connected to the first programmable logic device;

[0052] The first programmable logic device includes a memory inside, and the memory stores waveform data of a preset period;

[0053] The first programmable logic device is used to sample the waveform data of the preset period stored at a preset sampling frequency to obtain vertical resolution data of the sampling point, calculate and process the vertical resolution data of the sampling point according to the waveform control parameter, obtain the required arbitrary wave data, and send it to the digital-to-analog converter;

[0054] The digital-to-analog converter is used to perform digital-to-analog conversion on arbitrary wave data, generate corresponding analog signals and output them.

[0055] The vertical resolution is also called amplitude resolution, which specifies the vertical accuracy of the waveform obtained after the digital-to-analog conversion. The amplitude resolution specification is usually expressed as the number of bits; for example, 8 bits or 16 bits. The higher the vertical resolution, the finer the quantization of the voltage range.

[0056] In the embodiment of the present invention, in order to distinguish it from the quantum analyzer, the programmable logic device in the arbitrary waveform generator is called the first programmable logic device, and the programmable logic device in the quantum analyzer is called the second programmable logic device (specific implementation is described below).

[0057] The embodiment of the present invention is not limited to the specific hardware type of the first programmable logic device, and also does not limit the type of memory in the first programmable logic device. For example, the first programmable logic device may be a field programmable gate array (FPGA), a complex programmable logic device (CPLD), an erasable programmable logic device (EPLD), and the like.

[0058] In one embodiment, when the required arbitrary wave data is a Gaussian modulated sine wave;

[0059] The first programmable logic device includes a memory, wherein the memory stores sine wave data and Gaussian wave data of a preset period;

[0060] The first programmable logic device is used to calculate the sine wave data and Gaussian wave data selected at each sampling moment according to the input waveform control parameters, multiply the calculation results to obtain the Gaussian modulated sine wave data, and transmit the amplitude information of the Gaussian modulated sine wave to the digital-to-analog converter.

[0061] In one embodiment, the first programmable logic device is implemented by, for example, an FPGA.

[0062] The structure of FPGA usually consists of three programmable units and a static memory for storing programming data. These three programmable units are input / output blocks (IOBs), configurable logic blocks (CLBs), and interconnect resources (IRs). Their working states are all set by the data (bit stream) in the static memory that stores programming data.

[0063] During the bit parameter calibration stage of superconducting quantum computing and the actual execution of quantum computing algorithms, it is necessary to emit various forms of pulse waveform signals to the quantum chip. The pulse waveform signal may be a special waveform with a longer time or it may be a number of short pulse waveforms. At the same time, each set of experiments requires waveform acquisition and data analysis of the bit state. Some simple and basic quantum computing experiments, such as scanning of the cavity frequency (superconducting quantum bits are realized through superconducting resonant cavities, and the inherent frequency of this superconducting resonant cavity is called the cavity frequency) and scanning of the energy spectrum (applying a microwave signal to the superconducting quantum bit to control the energy state of the bit, and changing the microwave frequency to observe the spectrum of changes in the quantum bit energy level is called the energy spectrum), require a large number of emission and acquisition of RF signals.

[0064] In the arbitrary waveform generator provided by the embodiment of the present invention, hardware acceleration is performed through a first programmable logic device such as an FPGA, and the arbitrary waveform that is originally obtained through a large amount of computing work in the host computer is processed by the hardware of the FPGA to reduce the workload of the central processing unit. In the measurement and control of superconducting quantum bits, 1) a sine wave with arbitrary frequency, adjustable amplitude, adjustable phase, and adjustable duration is required. 2) a square wave with arbitrary frequency, adjustable amplitude, adjustable phase, and adjustable duration. 3) a triangular wave with arbitrary frequency, adjustable amplitude, adjustable phase, and adjustable duration. 4) a direct current with adjustable amplitude. 5) a Gaussian wave with adjustable amplitude and adjustable duration, and a Gaussian modulated sine wave.

[0065] In the embodiment of the present invention, the process of generating a waveform executed by the first programmable logic device of the arbitrary waveform generator, such as FPGA, is different from the existing host computer processing process, which is specifically described as follows:

[0066] When the user needs to generate the above waveform, he uses a high-level language such as a compiled or interpreted language, and the high-level language needs to be translated into a machine language by a compiler. According to the existing practice, the generation of the waveform is completed by the host computer. Inside the central processing unit (CPU) of the host computer, the instructions for generating the waveform are sequentially executed, and the next one is executed after one is executed. In the embodiment of the present invention, since FPGA is a programmable logic chip, it contains a large number of programmable logic units, memories, I / O ports and other resources. FPGA is pure hardware and uses a hardware description language. The integrated circuit is customized on the FPGA chip through the hardware description language.

[0067] Unlike the central processing unit, the FPGA is parallel inside, and all circuit logics are triggered by the same clock. The central processing unit and FPGA implement information processing and send control signals in different ways. The central processing unit responds to various external conditions through the main function or operating system to implement task scheduling, and outputs the corresponding state through software to achieve the normal operation of the electronic system, while the FPGA responds to various stimuli through pure hardware, which is different from the fundamental method of the central processing unit to achieve control. It has the advantages of strong programmability, fast computing speed, strong reliability and strong parallel processing capabilities. FPGA is often used to implement high-performance computing tasks such as digital signal processing, image processing, data compression, network communication, and deep learning.

[0068] Taking the aforementioned Gaussian modulated sine wave as an example, for example, the sine wave data and Gaussian wave data of a preset period are pre-stored in the FPGA, and the user enters 5 waveform control parameters in the host computer: S1, Gaussian waveform width S2, Gaussian modulated sine wave start time S3, sine wave frequency S4, sine wave phase S5, sine wave amplitude. The FPGA calculates the sine wave data and Gaussian wave data to be selected at each sampling moment according to the above waveform control parameters, and then multiplies the two to obtain the Gaussian modulated sine wave data, and finally directly transmits the amplitude information of each sampling point in the generated Gaussian modulated sine wave data from the FPGA to the DAC.

[0069] The waveform control parameters required to generate different forms of waveforms may be slightly different, and may generally include at least one of the parameters such as the width, frequency, phase, starting point, and amplitude of the wave, etc. The embodiment of the present invention does not limit this.

[0070] For example, an ideal sinusoidal signal S(t) can be expressed as:

[0071]

[0072] The above formula (1) shows that as long as the amplitude A and initial phase of the sine wave signal are unchanged, its spectrum is about f 0 To simplify the operation, we can set A = 1, That is, it does not affect the analysis of frequency. That is:

[0073] S(t)=sin(2πf o t)=sinω(t) (2)

[0074] In the formula,

[0075] ω(t)=2πf o t (3)

[0076] The signal of equation (2) is sampled with a sampling frequency of f s , the sampling period is T s , then we can get a discrete waveform sequence:

[0077] S(n)=sin(2πf o nT s ) (n=0,1,2,3......) (4)

[0078] The corresponding discrete sequence of phases is:

[0079] ω(n)=2πf o T s ·n=Δω·n (n=0,1,2,3...) (5)

[0080] It can be deduced that in the above formula (5),

[0081] Δω=2πf o T s =2πf o / f s (6)

[0082] Δω is the phase increment between two consecutive samples. According to the sampling theorem: The discrete sequence from equation (4) can uniquely restore the analog signal of equation (2). From equation (6), we can get:

[0083]

[0084] It can be seen that the output frequency is determined by the phase increment Δω between two samples. Therefore, as long as this phase increment (step size) is controlled, the frequency of the output signal can be controlled.

[0085] For example, if you want to calculate the data of a certain waveform in FPGA, and the input waveform control parameters include the frequency and amplitude of the waveform, the calculation process inside the FPGA can be as follows:

[0086] The waveform data of one cycle is stored in the random access memory (RAM) inside the FPGA in advance, and then the phase accumulator designed by the FPGA is used to calculate and select the data storage address in the RAM, and finally the frequency control word given by the data is output, and the arbitrary waveform output is realized through DAC conversion. Then, the original waveform generated by the FPGA is multiplied by the amplitude control word to obtain waveforms of different amplitudes.

[0087] From the above process, it can be seen that the process of FPGA processing and generating arbitrary waveform signals is closely related to its hardware structure. Compared with the processing method of the host computer, there are essential differences and the processing efficiency is higher.

[0088] In one embodiment, referring to Figure 2 As shown, the quantum analyzer includes: a second programmable logic device and an analog-to-digital converter electrically connected to the second programmable logic device; wherein:

[0089] The analog-to-digital converter is specifically used to collect the radio frequency analog signal obtained by monitoring the state of the quantum bit in the quantum chip each time, and perform analog-to-digital conversion on the radio frequency analog signal to obtain the corresponding digital signal and output it;

[0090] The second programmable logic device is used to extract a preset number of data points containing bit information from the digital signal output by the analog-to-digital converter, perform fast Fourier transform, obtain corresponding spectrum data, determine the frequency points corresponding to the data points from the spectrum data, and extract amplitude and phase data corresponding to the frequency points based on the frequency points, and transmit the extracted amplitude and phase data to the host computer.

[0091] In an embodiment of the present invention, it is considered to place the processing of information near the edge. In the scenario where the quantum analyzer collects signals, it can be understood as being close to where the data is generated, namely the analog-to-digital converter (ADC). All analog signal information will be converted into digital signals at the ADC. By searching along the direction of the data flow under the general architecture, it can be concluded that the second programmable logic device is the computing power closest to the edge for information processing.

[0092] The second programmable logic device is similar to the first programmable logic device, and may be implemented by using, for example, FPGA.

[0093] The second programmable logic device analyzes the data output by the analog-to-digital converter for each quantum bit state observation, removes the first and last preset number of data points (which may contain noise signals), and extracts the middle 2 N The data points are processed by Fast Fourier Transform (FFT) in FPGA, and 2 N The data points correspond to the frequency points and their amplitude and phase data are extracted.

[0094] The purpose of fast Fourier transform is to convert the time domain signal output by the analog-to-digital converter into a frequency signal.

[0095] The second programmable logic device sends the result of each observation to the host computer, and the host computer counts the observation results for a preset number of times (for example, 1000 times) and can analyze the probability that the quantum bit is in a preset quantum state, such as 0 state or 1 state.

[0096] When the quantum measurement and control system is relatively large and controls more quantum bits, compared with the situation where one host computer analyzes and calculates the data returned by all quantum analyzers, the problem is decomposed into many small parts by using distributed computing, and the second programmable logic device of each quantum analyzer, such as FPGA, calculates and analyzes the data collected by its own ADC. Such a parallel processing solution will have greater advantages. In the embodiment of the present invention, the work with very large computational workload is assigned to the second programmable logic device, such as FPGA hardware, to reduce the workload of the central processor in the host computer, thereby improving the efficiency of the entire system.

[0097] Continue to refer to Figure 2 As shown, the arbitrary waveform generator may further include: a first network port, the first network port is electrically connected to the first programmable logic device, and is used to connect to a switch outside the quantum measurement and control system, receive waveform control parameters from the switch and output them to the first programmable logic device;

[0098] The quantum analyzer may further include: a second network port; the second network port is electrically connected to the second programmable logic device and is used to connect to a switch outside the quantum measurement and control system, receive amplitude and phase data from the second programmable logic device, and transmit it to the host computer through the switch.

[0099] The first network port and the second network port may have a similar structure, for example, consisting of a network port and a network port chip.

[0100] In terms of specific hardware configuration, in an embodiment of the present invention, the arbitrary waveform generator and the quantum analyzer are respectively arranged on different boards; or the arbitrary waveform generator and the quantum analyzer are arranged on the same board.

[0101] In a possible embodiment, when the arbitrary waveform generator and the quantum analyzer are arranged on the same board, the first programmable logic device and the second programmable logic device are integrated into the same field programmable gate array.

[0102] In order to better illustrate the structure, working process, principle and technical effect of the above-mentioned quantum measurement and control system provided by an embodiment of the present invention, a specific example is given below.

[0103] Reference Figure 3As shown, the quantum measurement and control system includes an FPGA chip, a DAC chip and an ADC chip. The measurement and control system is connected to the host computer through an Ethernet switch. The quantum measurement and control system is used to transmit radio frequency signals to the quantum chip and collect the radio frequency signals of the quantum chip.

[0104] The FPGA chip, DAC chip and ADC chip are arranged on the same board, wherein the FPGA chip and DAC chip realize the functions of the aforementioned arbitrary waveform generator, and the FPGA chip and ADC chip realize the functions of the aforementioned quantum analyzer.

[0105] exist Figure 3 In the embodiment, the FPGA chip assumes the functions of the first programmable logic device and the second programmable logic device in the aforementioned embodiment, and it can also be understood that the first programmable logic device and the second programmable logic device are implemented by the same FPGA hardware.

[0106] Assuming that the sampling rates of the DAC chip in the arbitrary waveform generator and the ADC chip in the quantum analyzer are both 2Gsa / s, then transmitting a 100ns waveform requires transmitting 200 points of data, and collecting a 5us waveform requires transmitting 10,000 points of data.

[0107] Assume that the first channel of the arbitrary waveform generator is required to transmit a 100 MHz sine wave with a Gaussian modulation of 100 ns, and the sampling rate of the DAC chip on the arbitrary waveform generator board is 2 Gsa / s, and the sampling resolution is 16 bits.

[0108] According to the existing technology, Figure 4 As shown, the parameters to be input on the host computer are: S1, the width of the waveform; S2, the start time of the Gaussian modulated sine wave; S3, the frequency of the sine wave; S4, the phase of the sine wave; S5, the amplitude of the sine wave. Assuming that each parameter is represented by 16 bits, the total amount of input data on the host computer is 10B. The host computer will generate a pulse waveform file through CPU calculation, with a duration of 100ns, two data points per nanosecond (ns), a total of 200 data points, and each data point is still represented by 16 bits, so the data generated by the CPU is a total of 400B ( Figure 3The next step is to read the generated 400B data from the memory or hard disk and send it to the network port on the arbitrary waveform generator through the network port switch. The data enters the FPGA chip through the network port chip, and then is sent to the DAC chip by the FPGA chip high-speed serializer / deserializer (SERDES) interface. The DAC chip converts the digital signal into an analog RF signal and transmits it. If we consider the scenario where 100 arbitrary waveform generator boards control 100 superconducting quantum bits, the waveform data of each channel (one arbitrary waveform generator is one channel) is calculated by the host computer CPU according to the user input parameters, and then sent to each board in turn through the host computer network port.

[0109] In the embodiment of the present invention, Figure 3 As shown, by utilizing the computing power of FPGA, the five parameters S1 to S5 mentioned above can be input into the host computer, and the 10B data can be sent to the FPGA chip. A sine wave data described by P points and a Gaussian waveform described by M points are stored inside the FPGA chip. The sine wave data and Gaussian wave data to be selected at each sampling moment are calculated according to the waveform parameters, and then the two are multiplied to obtain a Gaussian modulated sine wave. Finally, the amplitude information of each sampling point generated is directly generated by the FPGA chip through calculation to generate the required 400B arbitrary wave data (awg_data) and sent to the DAC chip. Figure 3 and Figure 4 Through the above process, the data transmission volume between the host computer and the arbitrary waveform generator board is reduced from 400B to 10B, and the transmission speed is increased by 40 times, which greatly reduces the data throughput of Ethernet and shortens the processing time of transmitted data. At the same time, since there is an FPGA chip on each arbitrary waveform generator board, when the measurement and control system is relatively large and controls more quantum bits, compared with a host computer calculating the transmission waveforms required for all boards, the idea of ​​distributed computing is used to decompose the problem into many small parts. The FPGA chip on each board calculates the transmission waveform sequence required by the DAC chip that matches it. This solution will have greater advantages.

[0110] For data collection and analysis, suppose that the state of a superconducting quantum bit needs to be observed 1000 times to determine the quantum state of the quantum bit. Each time, a 5us waveform is collected using the first channel of the quantum analyzer board. The sampling rate of the ADC chip on the quantum analyzer board is 2Gsa / s.

[0111] According to the implementation method of the prior art, Figure 5As shown in the figure, 1000×2Gsa / s×5000ns=10M data points need to be transmitted. Assuming that each data point is represented by 16 bits, the total data volume of 10M data points is 20MB (as shown in the figure). Figure 5 The 20MB data is transmitted to the host computer through the FPGA chip and the network port chip on the quantum analyzer board and then through the Gigabit network port switch. The host computer divides the collected waveform into segments according to the number of experiments and then performs fast Fourier transform FFT. The corresponding frequency point of the signal is found in the spectrum after each Fourier transform, and its amplitude and phase are extracted to determine whether the quantum state is 0 or 1. The results of 1000 experimental observations can be statistically analyzed to obtain the probability of the quantum bit being in the 0 state and the 1 state.

[0112] In this example, refer to Figure 6 As shown in the figure, using the computing power of FPGA, we can analyze the data of each quantum bit state observation 2Gsa / s×5000ns=10K points, remove the first and last data points, and extract the 2 points in the middle containing bit information. N The data points are fast Fourier transformed in FPGA, and the corresponding frequency points of the signal are found from the spectrum data obtained by Fourier transform to extract its amplitude and phase. It is still assumed that each data is represented by 16 binary digits, and the time domain data that needs to be sent up in the prior art is converted into frequency domain data. Then the total amount of amplitude and phase data obtained in the frequency domain from one observation is 4B, and the total amount of data for observing the state of a superconducting quantum bit 1000 times is 4KB (refer to Figure 6 The 4KB data is transmitted to the host computer through the FPGA chip and the network port chip on the quantum analyzer board and then through the Gigabit network port switch. The results of 1000 experimental observations can be counted to obtain the probability of the quantum bit being in the 0 state and the 1 state. Through this process, Figure 5 and Figure 6 As shown in the figure, compared with the prior art, the data transmission volume between the quantum analyzer and the host computer is reduced from 20MB to 4KB, and the transmission speed is increased by 5000 times. At the same time, since there is an FPGA chip on each quantum analyzer board, when the measurement and control system is relatively large and needs to control more quantum bits, compared with a host computer calculating the data returned by all quantum analyzers, this example uses distributed computing to decompose the problem into many small parts. The FPGA chip on each board calculates and analyzes the data collected by its own ADC chip. Such a parallel processing solution will have greater advantages.

[0113] Based on the same inventive concept, the embodiments of the present invention also provide a quantum computer, a quantum computing system, a quantum communication network, and a quantum communication method. Since the principles of the problems solved by these devices and methods are similar to those of the aforementioned quantum measurement and control system, the implementation of the device method can refer to the implementation of the aforementioned quantum measurement and control system, and the repeated parts will not be repeated.

[0114] A quantum computer provided in an embodiment of the present invention includes the aforementioned quantum measurement and control system and quantum chip.

[0115] The above-mentioned quantum computer may also include an input device for inputting waveform control parameters.

[0116] A quantum computing system provided by an embodiment of the present invention includes: a host computer, a quantum measurement and control system, and a quantum chip; the host computer and the quantum measurement and control system are in communication connection; wherein:

[0117] A host computer, used to send waveform control parameters to the quantum measurement and control system, and obtain amplitude and phase data from the quantum measurement and control system, and analyze the probability that the quantum bit in the quantum chip is in a preset quantum state according to the amplitude and phase data;

[0118] A quantum measurement and control system, comprising: an arbitrary waveform generator and a quantum analyzer, wherein: the arbitrary waveform generator is used to receive waveform control parameters transmitted from a host computer, generate required arbitrary wave data according to the waveform control parameters, perform digital-to-analog conversion on the arbitrary wave data, generate corresponding analog signals and transmit them to a quantum chip; and / or the quantum analyzer is used to collect radio frequency analog signals from quantum chips, perform analog-to-digital conversion on the collected radio frequency analog signals to obtain corresponding digital signals, extract amplitude and phase data of preset frequency points in a frequency spectrum corresponding to the digital signal, and transmit the extracted amplitude and phase data to the host computer.

[0119] In one embodiment, the above quantum computing system may further include: a switch, wherein the switch is communicatively connected to the host computer and the quantum measurement and control system respectively.

[0120] An embodiment of the present invention further provides a quantum communication network, which includes at least one quantum computing system as described above.

[0121] An embodiment of the present invention also provides a method for performing quantum communication using the aforementioned quantum computing system.

[0122] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0123] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0124] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0125] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0126] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A quantum measurement and control system, comprising: At least one arbitrary waveform generator and at least one quantum analyzer, characterized in that the arbitrary waveform generator is used to receive waveform control parameters transmitted by the host computer, generate required arbitrary wave data according to the waveform control parameters, perform digital-to-analog conversion on the arbitrary wave data, generate corresponding analog signals and transmit them to the quantum chip to manipulate the quantum bits; The quantum analyzer is specifically used to collect the radio frequency analog signal obtained by each state monitoring of the quantum bit in the quantum chip, and perform analog-to-digital conversion on the radio frequency analog signal to obtain a corresponding digital signal; extract a preset number of data points containing bit information from the digital signal, perform fast Fourier transform to obtain corresponding spectrum data, determine the frequency point corresponding to the data point from the spectrum data, and extract the amplitude and phase data corresponding to the frequency point based on the frequency point, and transmit the extracted amplitude and phase data to the host computer.

2. The quantum measurement and control system according to claim 1, characterized in that: The arbitrary waveform generator includes: a first programmable logic device and a digital-to-analog converter electrically connected to the first programmable logic device; The first programmable logic device includes a memory, wherein the memory stores waveform data of a preset period; The first programmable logic device is used to sample the waveform data storing the preset period according to the preset sampling frequency to obtain the vertical resolution data of the sampling point, calculate and process the vertical resolution data of the sampling point according to the waveform control parameter, obtain the required arbitrary wave data, and send it to the digital-to-analog converter; The digital-to-analog converter is used to perform digital-to-analog conversion on the arbitrary wave data, generate a corresponding analog signal and output it.

3. The quantum measurement and control system according to claim 2, characterized in that: The required arbitrary wave data is a Gaussian modulated sine wave; The first programmable logic device includes a memory, wherein the memory stores sine wave data and Gaussian wave data of a preset period; The first programmable logic device is used to calculate the sine wave data and Gaussian wave data selected at each sampling moment according to the input waveform control parameters, multiply the calculation results to obtain Gaussian modulated sine wave data, and transmit the amplitude information of the Gaussian modulated sine wave to the digital-to-analog converter.

4. The quantum measurement and control system according to claim 2, characterized in that: The quantum analyzer includes: a second programmable logic device and an analog-to-digital converter electrically connected to the second programmable logic device; The analog-to-digital converter is specifically used to collect the radio frequency analog signal obtained by monitoring the state of the quantum bit in the quantum chip each time, and perform analog-to-digital conversion on the radio frequency analog signal to obtain and output the corresponding digital signal; The second programmable logic device is used to extract a preset number of data points containing bit information from the digital signal output by the analog-to-digital converter, perform fast Fourier transform, obtain corresponding spectrum data, determine the frequency points corresponding to the data points from the spectrum data, and extract the amplitude and phase data corresponding to the frequency points based on the frequency points, and transmit the extracted amplitude and phase data to the host computer.

5. The quantum measurement and control system according to claim 4, characterized in that: The arbitrary waveform generator further includes: a first network port, the first network port is electrically connected to the first programmable logic device, and is used to connect to a switch outside the quantum measurement and control system, receive the waveform control parameter from the switch and output it to the first programmable logic device; The quantum analyzer also includes: a second network port, which is electrically connected to the second programmable logic device and is used to connect to a switch outside the quantum measurement and control system, receive the amplitude and phase data from the second programmable logic device, and transmit it to the host computer through the switch.

6. The quantum measurement and control system according to any one of claims 2 to 4, characterized in that: The arbitrary waveform generator and the quantum analyzer are respectively arranged on different boards; or The arbitrary waveform generator and the quantum analyzer are arranged on the same board.

7. The quantum measurement and control system according to claim 4, characterized in that: The arbitrary waveform generator and the quantum analyzer are arranged on the same board, and the first programmable logic device and the second programmable logic device are integrated into the same field programmable gate array.

8. A quantum computer, characterized in that: It comprises a quantum measurement and control system and a quantum chip as described in any one of claims 1 to 7.

9. A quantum computing system, characterized in that: include: A host computer, a quantum measurement and control system and a quantum chip; the host computer and the quantum measurement and control system are in communication connection; wherein: The host computer is used to send waveform control parameters to the quantum measurement and control system, and obtain amplitude and phase data from the quantum measurement and control system, and analyze the probability that the quantum bit in the quantum chip is in a preset quantum state according to the amplitude and phase data; The quantum measurement and control system includes: an arbitrary waveform generator and a quantum analyzer, wherein: the arbitrary waveform generator is used to receive waveform control parameters transmitted from a host computer, generate required arbitrary wave data according to the waveform control parameters, perform digital-to-analog conversion on the arbitrary wave data, generate corresponding analog signals and transmit them to the quantum chip; and / or the quantum analyzer is used to collect radio frequency analog signals from the quantum chip, perform analog-to-digital conversion on the collected radio frequency analog signals to obtain corresponding digital signals, extract amplitude and phase data of preset frequency points in the frequency spectrum corresponding to the digital signal, and transmit the extracted amplitude and phase data to the host computer.

10. The quantum computing system according to claim 9, characterized in that Also includes: A switch is respectively communicatively connected with the host computer and the quantum measurement and control system.

11. A quantum communication network, characterized in that: The quantum communication network comprises at least one quantum computing system as claimed in claim 9 or 10.

12. A method for performing quantum communication using the quantum computing system according to claim 9 or 10.

Images