Device for quickly judging quantum bit state and sending feedback information

Abstract

The invention relates to the technical field of quantum information, in particular to a device for quickly judging a quantum bit state and sending feedback information, which comprises a processor module, a storage module and an ADC module, the ADC module is used for collecting and outputting a waveform signal, the processor module comprises a signal processing unit PSU and a logic processing unit PLU, and the processor module is connected with the storage module. The ADC module comprises an acquisition unit and an analog-to-digital conversion unit; the processor module rapidly analyzes the waveform signal output by the ADC module in a multi-window mode and generates feedback information, and the feedback information is transmitted to an external arbitrary waveform generator AWG. By dividing the waveform signal output by the ADC module into a plurality of signal segments, the PLU can process the signal in parallel, and allows a quantum system to pay attention to short-term fluctuation and long-term trend of the signal at the same time, so that more comprehensive signal characteristics are obtained, the data processing efficiency is improved, and the change of the quantum bit state can be quickly responded and adapted.

Description

Technical Field

[0001] The present invention relates to the field of quantum information technology, and in particular to a device for quickly determining the state of a quantum bit and sending feedback information. Background Art

[0002] In quantum fault-tolerant computing, AWG generates control waveform signals to manipulate the state of quantum bits. Since quantum systems are very sensitive to external interference, AWG is required to generate highly accurate and repeatable waveforms.

[0003] In order to adapt to different computing tasks and quantum algorithms, the AWG must be able to be flexibly configured to generate electrical signals of different shapes, frequencies, and phases. Quantum systems often require real-time feedback signals to correct errors so that the AWG can receive feedback information in a very short time (such as within a few nanoseconds) and select the next waveform to be played based on this information. The selection and adjustment of the control waveform needs to be completed within a few nanoseconds to tens of nanoseconds to ensure the accuracy and efficiency of quantum computing. Existing devices cannot meet the requirements for rapid judgment and feedback operations on bit states. Summary of the invention

[0004] The present invention supports multi-window analysis and processing of signals, thereby improving the speed of judgment and feedback.

[0005] The technical solution proposed in the present invention is: a device for quickly judging the state of a quantum bit and sending feedback information, comprising a processor module, a storage module and an ADC module, the ADC module is used to collect and output waveform signals, the processor module comprises a signal processing unit PSU and a logic processing unit PLU, the ADC module comprises an acquisition unit and an analog-to-digital conversion unit; the processor module uses a multi-window mode to quickly analyze the waveform signal output by the ADC module and generate feedback information, and the feedback information is transmitted to an external arbitrary waveform generator AWG.

[0006] Preferably, the ADC module is used to collect and output waveform signals, including: The acquisition unit acquires the measurement signal of the quantum bit according to a preset acquisition frequency; Obtain the wavelength and peak value of the control signal; Obtaining a modulus curve of a measurement signal; According to the wavelength and peak value of the control signal, a waveform curve corresponding to the state of the quantum bit is obtained; The acquired waveform curve is sent to the PSU of the processing module after analog-to-digital conversion, and the PLU obtains the waveform curve data after analog-to-digital conversion from the PSU and processes it.

[0007] Preferably, obtaining a waveform curve of the measurement signal according to the wavelength and peak value of the control signal includes: According to the peak value and wavelength of the control signal, each scanning peak point of the control signal is used as a preset measurement point, and a measurement signal is input to the target quantum bit at each measurement point; A simulated waveform curve is formed with the wavelength as the horizontal coordinate and the modulus of the measured signal as the vertical coordinate; Compare the simulated waveform curve with the standard control signal curve after aligning them on the time axis to determine multiple peak differences , calculate the average value of multiple peak differences ; The simulation curve with the smallest average value is selected as the waveform curve reflecting the state of the quantum bit.

[0008] Preferably, the processor module is used to establish data communication, including: The PSU communicates with the host computer via TCP / IP protocol; The PSU communicates with the external AWG via the Serial Peripheral Interface (SPI).

[0009] Preferably, analyzing the input signal of the ADC module and outputting a feedback result comprises: The waveform signal output by the ADC module is received through the PLU, and the waiting time for the upper computer's decoding request is maintained through the timer preset in the PSU; The PLU demodulates and feeds back the received waveform signal.

[0010] Preferably, the processor module uses a multi-window mode to quickly analyze the waveform signal output by the ADC module and generate feedback information, including: The PLU divides the waveform signal output by the ADC module into multiple signal segments through multiple windows; At the same time, the signal in each signal segment is preprocessed; Extract key features of the signal from the preprocessed signal segment to form a corresponding feature set; Performing pattern recognition on each feature set using a preset machine learning algorithm, wherein the machine learning algorithm includes one or more of a classification, clustering, and regression analysis algorithm; According to the pattern recognition results, the quantum bit state is determined and a feedback signal is output; The waveform signal and the output feedback signal are stored in the storage module.

[0011] Preferably, the processing module is a Zynq-7020z chip, and the reception of waveform data and trigger signals of the ADC module and the transmission of feedback signals all adopt a 2.5V low voltage differential signal LVDS25.

[0012] The present invention also provides a computer-readable storage medium, which is applied to the device for quickly determining the state of a quantum bit and issuing feedback information, wherein the computer-readable storage medium is used to store an executable program, and the executable program is executed by a computer to implement: The ADC module collects the measurement signal according to the set collection frequency f; Pre-store multiple windows and call the windows to divide the waveform signal into multiple signal segments; Pre-store a machine learning algorithm and call the machine learning algorithm to identify key information of each signal segment.

[0013] Beneficial effects of the present invention: 1. The present invention supports multi-window demodulation, and the number of demodulations can meet the needs of a quantum computing experiment (more than 20,000 times), while minimizing the time required for judgment and feedback. The entire process is within 500 ns, so that the surface code error correction cycle can be at the order of 1us.

[0014] 2. The processing module of the present invention supports simultaneous processing and feedback of data of multiple frequencies, and the enabled channels can be pre-set to support multi-channel reading of quantum bits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a module diagram of a device for quickly determining the state of a quantum bit and issuing feedback information according to the present invention. DETAILED DESCRIPTION

[0016] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0017] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0018] refer to Figure 1The technical solution provided by the present invention is: a device for quickly judging the state of a quantum bit and sending feedback information, comprising a processor module, a storage module and an ADC module, the ADC module is used to collect and output waveform signals, the processor module comprises a signal processing unit PSU and a logic processing unit PLU, the ADC module comprises an acquisition unit and an analog-to-digital conversion unit; the processor module uses a multi-window mode to quickly analyze the waveform signal output by the ADC module and generate feedback information, and the feedback information is transmitted to an external arbitrary waveform generator AWG.

[0019] The process of collecting and outputting waveform signals by the ADC module includes the following steps: The acquisition unit acquires the measurement signal of the quantum bit according to a preset acquisition frequency; Obtain the wavelength and peak value of the control signal; Obtaining a modulus curve of a measurement signal; According to the wavelength and peak value of the control signal, a waveform curve corresponding to the state of the quantum bit is obtained; The acquired waveform curve is sent to the PSU of the processing module after analog-to-digital conversion, and the PLU obtains the waveform curve data after analog-to-digital conversion from the PSU and processes it.

[0020] The process of obtaining the waveform curve of the measurement signal according to the wavelength and peak value of the control signal includes the following steps: According to the peak value or wavelength of the control signal, each scanning peak point of the control signal is used as a preset measurement point, and a measurement signal is input to the target quantum bit at each measurement point; for example, a wavelength-fixed peak value variation curve or a peak-fixed wavelength variation curve.

[0021] The measurement signal obtained at each measurement point is a three-dimensional vector, including a real part, an imaginary part and a modulus, which can be used to reflect the state of the quantum bit.

[0022] For example, a simulated waveform curve is formed with the wavelength as the abscissa and the modulus of the measured signal as the ordinate; Compare the simulated waveform curve with the standard control signal curve on the reference axis (time axis) and determine multiple peak differences , calculate the average value of multiple peak differences ; The simulation curve with the smallest average value is selected as the waveform curve reflecting the state of the quantum bit.

[0023] The PSU in the processor module communicates with the host computer through the TCP / IP protocol and communicates with the external AWG through the serial peripheral interface SPI.

[0024] The process of analyzing the input signal of the ADC module and outputting the feedback result includes the following steps: The waveform signal output by the ADC module is received through the PLU, and the waiting time for the upper computer's demodulation request is maintained through the timer preset in the PSU; the PLU analyzes and feeds back the received waveform signal.

[0025] In order to achieve the effect of fast reading, judgment and feedback, the processor module uses the multi-window mode to quickly analyze the waveform signal output by the ADC module and generate feedback information. The specific method is as follows: The PLU divides the waveform signal output by the ADC module into multiple signal segments through multiple windows; preprocesses the signal in each signal segment at the same time; extracts the key features of the signal from the preprocessed signal segments to form a corresponding feature set; performs pattern recognition on each feature set through a preset machine learning algorithm, and the machine learning algorithm includes one or more of classification, clustering and regression analysis algorithms; judges the state of the quantum bit according to the pattern recognition result, and outputs a feedback signal; stores the waveform signal and the output feedback signal in a storage module.

[0026] In this embodiment, multiple peak information of the signal in the signal segment is extracted, and after normalization processing, a key feature set of multiple peak information is formed. ,in, For the The feature set of the peak information of the segment signal segment, , Indicates the number of peaks.

[0027] Specifically, in a waveform signal, the characteristics of each data point (such as time, amplitude, etc.) can be used as input, and whether it is a peak point can be used as the output label to train an SVM classifier. By adjusting the parameters of the SVM, an optimal decision boundary can be found to distinguish between peak points and non-peak points, and peak points can be extracted.

[0028] In some embodiments, principal component analysis (PCA) can be combined with a clustering algorithm: first, PCA is used to reduce the dimension of the waveform signal to remove redundant information; then a clustering algorithm (such as K-means or DBSCAN) is used to perform cluster analysis on the reduced-dimensional data. By observing the clustering results, the cluster where the peak point is located can be identified, and the modulus value of the peak point can be further extracted.

[0029] After receiving the feedback signal, the AWG selects the waveform to be output next or loops to output the original waveform based on the state of the quantum bits in the feedback signal and the preset control process. After receiving the feedback signal, the AWG decodes it according to the preset decoding rules. The decoded data is input into the filter to eliminate noise or interference. The state information of the quantum bit is extracted from the sampled data, including the energy spectrum, frequency component or phase of the calculated signal.

[0030] The present invention also provides a computer-readable storage medium for storing an executable program, wherein the executable program is executed by a computer to implement: 1. Make the ADC module collect the measurement signal according to the set acquisition frequency f. Specifically, set a suitable acquisition frequency f according to actual needs and signal characteristics. This frequency should be high enough to capture the key features of the signal.

[0031] According to the selected acquisition frequency f, configure the relevant parameters of the ADC module, including setting the ADC clock source, frequency divider, trigger mode, etc. The specific configuration method depends on the type of ADC module and controller or processor used.

[0032] Set the working mode of the ADC module (such as single conversion mode or continuous conversion mode) and specify the acquisition frequency f. At the same time, it is also necessary to handle the interrupts or events generated by the ADC module in order to read the converted data.

[0033] When the ADC module starts collecting data, it is necessary to read the converted data regularly and store it in an appropriate data structure (such as an array or buffer). Then, this data can be used for subsequent signal processing and analysis.

[0034] Use DMA (direct memory access) technology to reduce the CPU load; use FIFO (first-in-first-out queue) to cache data to avoid data loss or overflow; and use more efficient algorithms or data structures to process data.

[0035] 2. Pre-store multiple windows and call the window to divide the waveform signal into multiple signal segments. Specifically: First, you need to define multiple windows, each of which represents a time scale or wavelength scale. The size of the window can be determined according to actual needs and the characteristics of the signal. For example, you can define windows of different sizes such as 10, 20, and 50. These windows will be used to divide the waveform signal into multiple signal segments. Store the defined windows for subsequent calls. This can be achieved by creating a list or array, in which each element is the size of a window. When processing the waveform signal, call the corresponding window as needed. For example, if you want to focus on the short-term fluctuations of the signal, you can choose a smaller window; if you want to focus on the long-term trend of the signal, you can choose a larger window. In this way, the signal can be processed in parallel at different time scales. Use the called window to divide the waveform signal into multiple signal segments. Specifically, the start position of the signal can be set to the start position of the current window, and then the length of the window can be moved to the right to get the next signal segment. Repeat this process until the entire signal is covered.

[0036] Process the segmented signal segments in parallel. This can be achieved through multi-threading or multi-process technology. Each thread or process is responsible for processing a signal segment and storing the results in a shared data structure (such as a list or dictionary).

[0037] When all threads or processes have finished processing, their results are merged. This can be done by traversing the shared data structure and extracting each element. The final result will contain the characteristics of the entire signal at different time scales.

[0038] In order to improve the efficiency of data processing, some optimization techniques can be used. For example, cache can be used to reduce repeated calculations; parallel computing frameworks (such as OpenMP or CUDA) can be used to speed up the calculation process; more efficient algorithms or data structures can also be used to process signals.

[0039] In summary, through the above steps, the function of pre-storing multiple windows and dividing the waveform signal into multiple signal segments can be realized. This multi-window mode allows the system to process signals in parallel, improving the efficiency of data processing. At the same time, through multi-window analysis, the system can focus on both the short-term fluctuations and long-term trends of the signal, thereby obtaining more comprehensive signal characteristics.

[0040] 3. Pre-store machine learning algorithms and call them to identify key information of each signal segment. For example, identify the modulus of the peak point of each signal segment, compare it with the expected modulus value, and determine whether the state of the quantum bit reaches the expected value.

[0041] In some preferred embodiments, the processing module may select a Zynq-7020z chip, and the waveform data and trigger signal reception of the ADC module and the transmission of the feedback signal all use a 2.5V low voltage differential signal LVDS25.

[0042] The embodiments disclosed in the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. The embodiments disclosed in the present invention include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part, and / or installed from a removable medium. When the computer program is executed by the central processing unit (CPU), the above-mentioned functions defined in the method of the present application are executed. It should be noted that the above-mentioned computer-readable medium of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of an electrical, magnetic, optical, electromagnetic, infrared segment, or semiconductor, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection with one or more wire segments, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In the present application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, electrical wire, optical cable, RF, etc., or any suitable combination of the foregoing.

[0043] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0044] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments. Without departing from the principles, the implementation methods of the present invention may be deformed or modified in any way.

Claims

1. A device for quickly determining the state of a quantum bit and issuing feedback information, characterized in that: It includes a processor module, a storage module and an analog-to-digital conversion ADC module. The ADC module is used to collect and output waveform signals. The processor module includes a signal processing unit PSU and a logic processing unit PLU. The ADC module includes an acquisition unit and an analog-to-digital conversion unit. The processor module uses a multi-window mode to quickly analyze the waveform signal output by the ADC module and generate feedback information. The feedback information is transmitted to an external arbitrary waveform generator AWG.

2. A device for quickly determining the state of a quantum bit and issuing feedback information according to claim 1, characterized in that: The ADC module is used to collect and output waveform signals, including: The acquisition unit acquires the measurement signal of the quantum bit according to a preset acquisition frequency; Obtain the wavelength and peak value of the control signal; Obtaining a modulus curve of a measurement signal; According to the wavelength and peak value of the control signal, a waveform curve corresponding to the state of the quantum bit is obtained; The acquired waveform curve is sent to the PSU of the processing module after analog-to-digital conversion, and the PLU obtains the waveform curve data after analog-to-digital conversion from the PSU and processes it.

3. A device for quickly determining the state of a quantum bit and issuing feedback information according to claim 2, characterized in that: The step of obtaining a waveform curve of the measurement signal according to the wavelength and peak value of the control signal comprises: According to the peak value and wavelength of the control signal, each scanning peak point of the control signal is used as a preset measurement point, and a measurement signal is input to the target quantum bit at each measurement point; A simulated waveform curve is formed with the wavelength as the horizontal coordinate and the modulus of the measured signal as the vertical coordinate; Compare the simulated waveform curve with the standard control signal curve after aligning them on the time axis to determine multiple peak differences , calculate the average value of multiple peak differences ; The simulation curve with the smallest average value is selected as the waveform curve reflecting the state of the quantum bit.

4. A device for quickly determining the state of a quantum bit and issuing feedback information according to claim 1, characterized in that: The processor module is used to establish data communication, including: The PSU communicates with the host computer via TCP / IP protocol; The PSU communicates with the external AWG via the Serial Peripheral Interface (SPI).

5. A device for quickly determining the state of a quantum bit and issuing feedback information according to claim 4, characterized in that: The step of analyzing the input signal of the ADC module and outputting a feedback result includes: The waveform signal output by the ADC module is received through the PLU, and the waiting time for the upper computer's decoding request is maintained through the preset timer in the PSU; The PLU demodulates and feeds back the received waveform signal.

6. A device for quickly determining the state of a quantum bit and issuing feedback information according to claim 5, characterized in that: The processor module uses a multi-window mode to quickly analyze the waveform signal output by the ADC module and generate feedback information, including: The PLU divides the waveform signal output by the ADC module into multiple signal segments through multiple windows; At the same time, the signal in each signal segment is preprocessed; Extract key features of the signal from the preprocessed signal segment to form a corresponding feature set; Performing pattern recognition on each feature set using a preset machine learning algorithm, wherein the machine learning algorithm includes one or more of a classification, clustering, and regression analysis algorithm; According to the pattern recognition results, the quantum bit state is determined and a feedback signal is output; The waveform signal and the output feedback signal are stored in the storage module.

7. A device for quickly determining the state of a quantum bit and issuing feedback information according to claim 1, characterized in that: The processing module is a Zynq-7020z chip, and the waveform data and trigger signal reception of the ADC module and the transmission of the feedback signal all adopt a 2.5V low voltage differential signal LVDS25.

8. A computer-readable storage medium, applied to a device for quickly determining a quantum bit state and issuing feedback information as claimed in any one of claims 1 to 7, characterized in that: The computer-readable storage medium is used to store an executable program, and the executable program is executed by a computer to implement: The ADC module collects the measurement signal according to the set collection frequency f; Pre-store multiple windows and call the windows to divide the waveform signal into multiple signal segments; Pre-store a machine learning algorithm and call the machine learning algorithm to identify key information of each signal segment.

Images