JP2024019231A - Method, device, apparatus, and storage medium for calibrating excitation frequency of quantum bit - Google Patents

Abstract

To provide a method for calibrating an excitation frequency of a quantum bit capable of obtaining an excitation frequency with higher accuracy by a small number of times of tests and improving efficiency of calibration when accurately calibrating the excitation frequency of a multi-quantum bit by a method with automated processing.SOLUTION: A method includes the steps of: exciting a target quantum bit with an excitation pulse having respective different pulse amplitude values for each sweep test frequency, and calculating average excitation rate based on a statistical excitation result indicating whether the target quantum bit has been successfully excited; determining a frequency spectral line of the target quantum bit based on each average excitation rate; and calibrating a target sweep test frequency of a unimodal waveform in the frequency spectral line as an excitation frequency of the target quantum bit.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to the field of quantum technology, and specifically to the technical field of superconducting quantum computers, quantum chips, quantum bits, frequency calibration, etc., and in particular, methods, devices, electronic devices, and computers for calibrating the excitation frequency of quantum bits. The present invention relates to readable storage media and computer programs.

After a superconducting qubit has been manufactured, there may be some variation between its bit frequency and the design value due to problems in the microfabrication process. In addition to this, some superconducting qubits are frequency tunable, and in practical use, the frequency of the bit needs to be adjusted according to the actual situation. Therefore, testing and calibration of superconducting qubit frequencies is very important.

How to ensure that high-quality bit excitation spectra are obtained by sweeping in sweep experiments, thereby quickly and accurately identifying the bit frequency, is an important issue in the representation and calibration of superconducting quantum chips. Especially as the number of qubits increases, automated representation and calibration procedures require more robust bit frequency sweeping methods.

Embodiments of the present disclosure provide methods, apparatus, electronic devices, computer-readable storage media, and computer program products for calibrating the excitation frequency of a qubit.

According to a first aspect, embodiments of the present disclosure include exciting the target qubit with excitation pulses having different pulse amplitude values for each sweep test frequency, and calculating an average excitation rate based on the statistical excitation results indicating whether or not the qubit is excited; determining frequency spectral lines of the target qubit based on each of the average excitation rates; A method for calibrating an excitation frequency of a qubit is proposed, comprising: calibrating a target sweep test frequency of a unimodal waveform as an excitation frequency of a target qubit.

According to a second aspect, embodiments of the present disclosure include exciting the target qubit with excitation pulses having different pulse amplitude values for each sweep test frequency, and determining whether the target qubit is successfully excited or not. a varied amplitude pulse excitation unit configured to calculate an average excitation rate based on the statistical excitation results indicating the excitation rate, and to determine a frequency spectral line of the target qubit based on each of the average excitation rates. excitation of the qubit, comprising a frequency spectral line creation unit configured and an excitation frequency calibration unit configured to calibrate a target sweep test frequency of a unimodal waveform in the frequency spectral line as an excitation frequency of the target qubit; An apparatus for frequency calibrating is proposed.

According to a third aspect, embodiments of the present disclosure provide an electronic device including at least one processor and a memory communicatively connected to the at least one processor, the memory including at least one processor. A method of calibrating an excitation frequency of a qubit according to any embodiment of the first aspect in at least one processor, wherein instructions executable by the processor are stored and the instructions are executed by the at least one processor. An electronic device that achieves this is proposed.

According to a fourth aspect, embodiments of the present disclosure store computer instructions for causing a computer to perform a method for calibrating an excitation frequency of a qubit according to any embodiment of the first aspect. A non-transitory computer-readable storage medium is proposed.

According to a fifth aspect, embodiments of the present disclosure include a computer in which, when executed by a processor, the method for calibrating the excitation frequency of a qubit according to any embodiment of the first aspect is implemented. A computer program product including a program is proposed.

The method of calibrating the excitation frequency of a qubit provided by the present disclosure replaces the conventional sweep test method of repeatedly testing multiple times based only on a fixed pulse amplitude value for each sweep test frequency in the process of a sweep experiment. to perform sweep tests based on pulses with amplitude values of By testing each pulse with a pulse amplitude value, relatively accurate excitation frequencies can be obtained with a relatively small number of tests, and highly accurate calibration of multi-qubit excitation frequencies can be achieved using automated processes. The efficiency of completed calibration can be improved.

Note that the content described in the summary of the invention is not intended to limit key features or important features of the embodiments of the present disclosure, nor does it limit the scope of the present disclosure. Other features of the disclosure will become easier to understand from the following description.

Other features, objects and advantages of the present disclosure will become more apparent from reading the detailed description of non-limiting embodiments made with reference to the following drawings.
1 is a diagram illustrating an example system architecture to which the present disclosure may be applied; FIG. 3 is a flowchart of a method for calibrating the excitation frequency of a qubit according to an embodiment of the present disclosure. FIG. 3 is a diagram showing an example of a one-dimensional frequency spectrum line created after implementing the calibration method shown in FIG. 2 according to an embodiment of the present disclosure. 3 is a schematic diagram of a Bloch sphere representation obtained corresponding to the calibration method shown in FIG. 2 according to an embodiment of the present disclosure; FIG. 5 is a flowchart of another method for calibrating the excitation frequency of a qubit according to an embodiment of the present disclosure. 3 is a flowchart of a method for calibrating and obtaining an excitation frequency range based on a unimodal waveform according to an embodiment of the present disclosure. 1 is a structural block diagram of an apparatus for calibrating the excitation frequency of a quantum bit according to an embodiment of the present disclosure. FIG. 1 is a structural schematic diagram of an electronic device suitable for carrying out a method for calibrating the excitation frequency of a qubit according to an embodiment of the present disclosure; FIG.

The following describes exemplary embodiments of the present disclosure with reference to the drawings, and various details of embodiments of the present disclosure are described herein to aid in understanding, but are merely exemplary. You should understand that there is no such thing. Accordingly, it should be understood that various changes and modifications can be made to the embodiments herein by those skilled in the art without departing from the scope and spirit of the disclosure. Note that, in the following description, for clarity and simplification, descriptions of known functions and structures will be omitted. Note that embodiments of the present disclosure and features in the embodiments can be combined with each other unless a contradiction occurs.

In the technical solution of the present disclosure, the collection, storage, use, processing, transmission, provision, disclosure, and other processes of related user personal information comply with the provisions of relevant laws and regulations, and do not violate public order and morals.

FIG. 1 illustrates an exemplary system architecture 100 in which embodiments of methods, apparatus, electronic devices, and computer-readable storage media for calibrating the excitation frequency of qubits according to the present disclosure may be applied.

As shown in FIG. 1, system architecture 100 may include a quantum chip 101, a frequency calibration device 102, and a server 103. The frequency calibrating device 102 emits excitation pulses according to set parameters, uses these excitation pulses to try to excite each quantum bit constituting the quantum chip 101, and collects and obtains excitation results. Frequency calibrating device 102 may send the excitation results to server 103 for subsequent calculations in order to calibrate the excitation frequency of the qubit based on the calculation results.

A user can collaboratively calibrate the frequency of the qubits in the quantum chip 101 using the frequency calibration device 102 and the server 103. Various applications may be installed in the frequency calibration device 102 and the server 103 to realize information communication between them, such as an excitation pulse parameter setting system application, an automated processing sweep experiment system application, and an excitation pulse parameter setting system application. Examples include results processing applications.

Frequency calibration device 102 is typically a dedicated hardware device. The server 103 may be hardware or software. If the server 103 is hardware, it may be implemented as a distributed server cluster composed of a plurality of servers, or it may be implemented as a single server. If server 103 is software, it may be implemented as multiple software or software modules, a single software or software module. No specific limitations are made here.

The frequency calibration device 102 and the server 103 can provide various services through various built-in applications. Taking a frequency calibration-based application that can provide automated qubit frequency calibration services as an example, the frequency calibration device 102 and the server 103 can achieve the following effects when the frequency calibration-based application runs. I can do it. First, the frequency calibration device 102 can excite the target qubit with excitation pulses having different pulse amplitude values for each sweep test frequency, and can transmit the statistical excitation results to the server 103. The excitation result is used to indicate whether the target qubit was successfully excited or not. If the target qubit is successfully excited, it enters an excited state. Server 103 can then calculate an average excitation rate based on the excitation results. Server 103 can then determine the frequency spectral lines of the target qubit based on each average excitation rate. Finally, the server 103 calibrates the target sweep test frequency of the unimodal waveform in the frequency spectrum line as the excitation frequency of the target qubit.

The method of calibrating the excitation frequency of a qubit provided by subsequent embodiments of the present disclosure typically involves a frequency calibration device 102 providing configured excitation pulses and a server 103 providing data processing capabilities. The devices that are jointly executed and correspondingly calibrate the excitation frequencies of the qubits may typically be installed separately in both. Note that the server 103 that provides data processing capability may be integrated into the frequency calibration device 102 as a calculation module. In this case, a device for calibrating the excitation frequency of the qubit would be installed in the frequency calibration device 102.
It should be understood that the number of quantum chips, frequency calibration devices, and servers in FIG. 1 is exemplary only. The number of quantum chips, frequency calibration devices, and servers may be increased or decreased depending on implementation needs.

Reference is made to FIG. 2, which is a flowchart of a method for calibrating the excitation frequency of a qubit according to an embodiment of the present disclosure. Flow 200 includes the following steps.

In step 201, a target qubit is excited with excitation pulses having different pulse amplitude values for each sweep test frequency, and an average excitation rate is calculated based on the statistical excitation results.

In this step, the excitation frequency of the target qubit is determined by the executor of the method for calibrating the excitation frequency of the qubit (for example, an integrated device that integrates the functions provided by the frequency calibration device 102 and the server 103 shown in FIG. 1). In a sweep experiment to determine Excitation is attempted and the statistical excitation result (used to indicate whether the target qubit was successfully excited or not successfully excited), of which successful excitation specifically indicates that the target qubit is The purpose is to calculate the average excitation rate based on the transition from an unexcited state to an excited state under the influence of an excitation pulse. Here, this excitation pulse can choose to use a π pulse or other pulses with similar properties, and this average excitation rate is performed at a certain sweep test frequency and at different pulse amplitude values. It is calculated by averaging the results of multiple excitation attempts (i.e., it is the quotient of the number of successful excitations divided by the total number of excitation attempts).

Specifically, in sweep experiments, multiple frequencies covering a certain frequency range are often selected as the sweep test frequency, and at each sweep test frequency, the excitation pulse parameters are fixed pulse length and different pulse amplitudes. and these different pulse amplitudes are the minimum pulse amplitude (-1, the reduced value and has no units) and the maximum pulse amplitude (+1, the reduced value and has no units). The value is obtained by selecting within the range (including the minimum value and the maximum value) (including the minimum value and the maximum value), and there may be multiple methods for specific selection. You may select multiple pulse amplitude values that increase gradually up to a value, or you may select multiple pulse amplitude values that decrease gradually from a maximum pulse amplitude value to a minimum pulse amplitude value (i.e., ), the pulse amplitude value may be selected upward from a specific small pulse amplitude value close to the minimum pulse amplitude value, or may be selected downward from a specific large pulse amplitude value close to the maximum pulse amplitude value. (i.e., at most one of the minimum and maximum values is selected). Based on this, the width of the upward or downward adjustment can be fixed, variable (or non-fixed), and repeated for each selected pulse amplitude value. (i.e., the excitation pulse is repeatedly issued multiple times with that pulse amplitude value). Thereby, it is possible to determine the excitation rate with high accuracy based on the excitation result fed back by the excitation pulse issued repeatedly, and furthermore, the number of repetitions of different pulse amplitude values is the same. They may be different or may not be partially the same, and can be set flexibly depending on the actual situation.

In step 202, frequency spectral lines of the target qubit are determined based on each of the average excitation rates.

Based on step 201, the purpose of this step is for the execution entity to generate and obtain a frequency spectrum line corresponding to the target qubit based on the average excitation rate corresponding to each of the sweep test frequencies. .

Specifically, for simplification, the frequency spectrum line may be expressed as a one-dimensional frequency spectrum line. For example, frequency can be a parameter on the X-axis and average excitation rate can be a parameter on the Y-axis, see the schematic diagram shown in FIG.

In step 203, the target sweep test frequency of the unimodal waveform in the frequency spectrum line is calibrated as the excitation frequency of the target qubit.

Based on step 202, this step aims at calibrating a target sweep test frequency corresponding to the unimodal waveform part in the frequency spectrum line as the excitation frequency of the target qubit by the execution entity. Briefly, only the target sweep test frequency corresponding to the peak in the unimodal waveform (ie, the sweep test frequency with the highest average excitation rate) can be determined as the optimal excitation frequency for the target qubit.

In addition, the reason why a more accurate excitation frequency can be determined based on the above method by selecting different pulse amplitude values to generate different excitation pulses and using them to try to excite the target qubit is that in the conventional technology, Typically, in a sweep experiment, a target qubit is repeatedly excited N times based on the same excitation pulse corresponding to a fixed pulse amplitude value, e.g., all of the amplitude values are 1 (maximum pulse amplitude). In contrast to generating an excitation pulse according to a sequence of pulse amplitude values that includes N pulses, in this embodiment, the sequence of pulse amplitude values is divided into a plurality of different pulse amplitudes selected between [-1, 1]. This is because it is possible to adjust it to a sequence consisting of values, for example, specifically [-1, ..., -0.9, ..., 0, ...0.1, ..., 1]. . That is, each pulse amplitude value in the adjusted pulse amplitude value sequence is not only arranged in ascending order from the smallest amplitude value to the largest amplitude value, but also expressed as a whole as an arithmetic progression of length N. , when excited in this way, if the tolerance of this arithmetic progression is sufficiently small, speaking from the Bloch sphere representation, the state of the bit is actually traversed and excited at each position on the YZ plane. , averaged, the statistical mean value of the z-axis projection is 0.5 (you may refer to the schematic diagram in FIG. 4). The effectiveness of this approach can be verified by numerical simulations in which each experimental point is excited with a sequence of amplitude values for an arbitrarily set length and the average value is taken. The results of such a sweep method showed obvious robustness. As shown in FIG. 3, a stable unimodal structure can be obtained using the same sequence for arbitrarily selected pulse lengths. This is in contrast to conventional results using a single amplitude value, which typically exhibit bimodal or multimodal waveforms in the frequency spectrum lines.

The method of calibrating the excitation frequency of a qubit provided by the embodiments of the present disclosure is a sweep test method in which repeated tests are performed multiple times based only on conventional fixed pulse amplitude values for each sweep test frequency in the course of a sweep experiment. to perform a sweep test based on pulses with varying amplitude values, thereby avoiding as much as possible the problem of reduced test efficiency due to the low precision of the selected fixed pulse amplitude values, i.e. By trying each pulse with a different pulse amplitude value, a relatively accurate excitation frequency can be obtained with a relatively small number of tests, and automated methods can provide highly accurate calibration of the excitation frequency of multiple qubits. The efficiency of completed calibration can be improved.

Next, refer to FIG. 5. FIG. 5 is a flowchart of another method for calibrating the excitation frequency of a qubit according to an embodiment of the present disclosure. Flow 500 includes the following steps.

In step 501, for each sweep test frequency, a target qubit is activated with each of the excitation pulses having pulse amplitude values constituting a preset sequence of pulse amplitude values, each under a predetermined pulse length corresponding to the current frequency. Excite and calculate the average excitation rate based on the statistical excitation results.

Unlike step 201, this step is performed by the executing entity for each sweep test frequency (i.e., a plurality of different test frequencies are set in advance in the sweep experiment) in the sweep experiment to identify the excitation frequency of the target qubit. ), the target qubit is excited with each excitation pulse having a pulse amplitude value constituting a preset pulse amplitude value sequence under a predetermined pulse length corresponding to the current frequency, and the The purpose is to calculate the average excitation rate based on the obtained excitation results. The execution entity is configured such that for each sweep test frequency, a corresponding predetermined pulse length and a preset pulse amplitude value sequence are preset, that is, each pulse amplitude value corresponds to the current sweep test frequency. , included in a preset sequence of pulse amplitude values at a predetermined pulse length.

Specifically, the different pulse amplitude values may be arranged in ascending order of amplitude value magnitude in a preset pulse amplitude value sequence, and conversely, the different pulse amplitude values may be arranged in ascending order of amplitude value magnitude in a preset pulse amplitude value sequence. In other words, by ordering, the adjustment range of each pulse parameter adjustment is made as small as possible, and the accuracy of the parameter adjustment result is ensured. Additionally, each of the pulse amplitude values ordered in the sequence may further constitute an arithmetic progression (i.e., the difference in amplitude value between two different adjacent pulse amplitude values is the same). Of course, an arithmetic sequence may be constructed with different amplitude differences, and can be selected flexibly according to the actual situation. At the same time, in addition to each pulse amplitude value appearing only once in the preset pulse amplitude value sequence, each pulse amplitude value may also exist N times in the preset pulse amplitude value sequence. It is also possible to comprehensively identify a more accurate excitation rate from the excitation results fed back by excitation pulses issued multiple times, and furthermore, to determine each pulse amplitude value. The corresponding N values may be the same or different, and may be set depending on the actual situation in which the accuracy of the excitation rate of the excitation results returned from pulse amplitude values of different magnitudes is different.

In step 502, frequency spectral lines of the target qubit are determined based on each of the average excitation rates.

In step 503, the target sweep test frequency of the unimodal waveform in the frequency spectrum line is calibrated as the excitation frequency of the target qubit.

The above steps 502 to 503 correspond to steps 202 to 203 shown in FIG. 2, and for the contents of the same parts, please refer to the corresponding parts in the previous embodiment. The explanation will be omitted here.

In step 504, in response to completion of excitation frequency calibration for all target qubits on the quantum chip of the superconducting quantum computer, a calibration completion mark is added to the quantum chip.

Based on step 503, this step determines by the execution entity whether all target qubits on the quantum chip of the superconducting quantum computer have completed the excitation frequency calibration according to the above scheme; The purpose is to add a calibration completion mark to the quantum chip after confirming that all excitation frequency calibrations have been completed.

In step 505, a calculation task is performed using the quantum chip to which the calibration completion mark has been added.

Based on step 504, the purpose of this step is to execute a calculation task by the execution entity using the quantum chip to which the calibration completion mark has been added. In other words, if the calibration completion mark is added to one quantum chip, it means that the quantum chip has the ability to process the calculation task at least within the validity period of the calibration completion, It becomes possible to participate in the task assignment and processing scene as a callable or allocatable resource, ensuring the accuracy of the calculation results.

Compared to the embodiment shown in FIG. 2, the present embodiment describes how to generate different excitation pulses used in an attempt to excite a target qubit in the course of a sweeping experiment based on a sequence of pulse amplitude values in step 501. By using the sequence format, not only can different pulse amplitudes be sorted according to the amplitude magnitude, but also the repetition situation can be better realized. At the same time, it is convenient for a computer that specifically executes the execution to accurately identify the execution order and accurately execute the execution according to the execution order. The present embodiment further extends the entire calibration scheme to the quantum chip availability marking scene by steps 504 and 505 to reveal which quantum chips are available after being calibrated; This makes it possible to ensure the accuracy of the calculation results.

Based on any of the embodiments described above, taking into account that the excitation frequency of a qubit is often not a fixed single value, it is possible to bring the qubit into an excited state in a specific frequency range. In this embodiment, FIG. 6 also shows a method for calibrating an excitation frequency range based on a unimodal waveform, the flow 600 of which includes the following steps.

In step 601, a unique unimodal waveform that exists in the frequency spectrum line is identified.

In step 602, a wavelength band higher than a band corresponding to a preset excitation rate in the unimodal waveform is determined as an excitation wavelength band.

In step 603, the target sweep test frequency corresponding to the excitation wavelength band is calibrated as the excitation frequency of the target qubit.

That is, the present embodiment first finds a uniquely existing unimodal waveform based on the waveform indicated by the frequency spectral line, and then finds a completely unimodal waveform higher than the band corresponding to the preset excitation rate of the complete unimodal waveform. The band can be determined as the excitation wavelength band, and finally the target sweep test frequency corresponding to the excitation wavelength band can be calibrated as the excitation frequency of the target qubit.

For better understanding, this disclosure further combines a specific application scene and explains the solution by way of example and numerical simulation.

In the original sweep experiment, each experimental point was obtained by shots (referring to short-time excitation of the excitation pulse) repeated N times, i.e., the pulse amplitude values were [1, 1, 1, 1, ..., 1]. , where the excitation pulse amplitude values corresponding to N shots at each point are respectively changed to [-1,...,-0.9,...,0,...0.1,...,1], and the length is is an arithmetic progression where N is N, that is, the maximum value of the above sequence is 1 (normally, the amplitude value of the XY pulse is a reduced value without a unit).

When excited in this way, if the tolerance of the arithmetic progression is small enough, the Bloch sphere representation actually traverses the state of the bit to each position on the YZ plane to excite it, and then takes the average. , the statistical mean of the z-axis projection should be 0.5 (you may refer to the schematic diagram in FIG. 4).

For any chosen pulse length, by sweeping in the form of a sequence of amplitude values, each experimental point is an averaged result, so no matter what the pulse length, for the same sequence, the same sequence In both cases, a unimodal structure can be obtained. This is in contrast to previous results using a single amplitude value.

Moreover, the results are not sensitive to the maximum value of the sequence, so setting the maximum value of one sequence arbitrarily can stably obtain a unimodal structure, and this realization method can be integrated into automated calibration methods. By doing so, it can be predicted that a very significant efficiency improvement effect will be obtained. The length of the excitation pulse was made to match the numerical simulation in Figure 3, and the maximum value of the sequence was tested under 1x π pulse amplitude and 2x π pulse amplitude, respectively, and the amplitude values in the sequence format were used for the sweep. Similarly, stable unimodal results that are not sensitive to initial parameters can be seen when using the method of taking the average.

In order to more clearly illustrate the differences with the prior art and the effects brought about by it, we will present a simulation of the results obtained by the sequence amplitude method provided by the present disclosure and the results obtained by performing a direct sweep with the fixed amplitude method. After comparing using a three-dimensional graph method (for example, using a Gaussian envelope for both excitation pulses) and actually comparing, the following can be discovered.

1) The results of the sequence amplitude method provided in this disclosure showed that the one-dimensional spectrum still maintains a single peak even if it changes according to the maximum value of the sequence.

2) As a result obtained by performing a direct sweep using the fixed amplitude method, two peaks, three peaks, etc. appeared in a fairly large area as the amplitude changed.

Furthermore, what needs to be verified is whether the signal-to-noise ratio of the average result of the current experiment with sequence length N is lower than that of the conventional experiment with the same amplitude repeated N times. The simulation results showed that as the number of slices increased, the results tended to become more stable and unimodal, and the peak width became smaller. This is due to the difference in the distribution density and uniformity of the state of the bit in the YZ cross section of the Bloch sphere, so the length of the arithmetic progression must be at least greater than 6 (for example, 6 to 10). That is, normally, a stable sharp single peak can be obtained only when the slice length is greater than 6.

From another angle, noise also needs to be considered in experiments. Regarding the readout noise, the data points used in the scheme provided by this disclosure are also average values taken over multiple shots, and the white noise in the readout signal is also suppressed by the statistical average value, so that no extraneous No additional read noise is added. However, when considering thermal excitation of bits, quantum decoherence, etc., the arithmetic progression becomes [-a, -a, -a, -b, -b, -b, ...b, b, b, a, a, a]. The number of repetitions representing the number of times each element in the sequence is repeated may be defined as n. The product of the number of repetitions and the arithmetic sequence length L is the total number of shots at each point, that is, n*L=N. An increase in the number of shots leads to an increase in experiment time and occupies the quantum computer's resources, so N needs to be made as small as possible. Further, since L needs to be larger than 6 in numerical simulation, the number of repetitions n is equal to or less than N/6. In order to ensure the signal-to-noise ratio, the upper limit of the number of repetitions is preferably n=N/6, so that the entire amplitude value sequence can be determined directly.

In actual sweep experiments, the length of the excitation pulse and the maximum value of the sequence can be chosen arbitrarily, for example, t and Amax, respectively, and in order to balance the peak width and decoherence, t is generally is selected to be 1 μs. Each experimental point is generated by averaging the results of N shots, and the corresponding amplitude values of these N shots are [-Amax, -Amax, . ．． ．． , -2Amax/3,. ．． ．． ,2Amax/3,Amax,. ．． ．． , Amax].

With further reference to FIG. 7, as an implementation of the method illustrated in the figures above, the present disclosure provides an embodiment of an apparatus for calibrating the excitation frequency of a qubit, an embodiment of which is illustrated in the figures. 2, and the device can be specifically applied to various electronic devices.

As shown in FIG. 7, an apparatus 700 for calibrating the excitation frequency of a quantum bit according to the present embodiment may include a variable amplitude value pulse excitation unit 701, a frequency spectrum line creation unit 702, and an excitation frequency calibration unit 703. . Among them, the variable amplitude value pulse excitation unit 701 excites the target qubit with excitation pulses having different pulse amplitude values for each sweep test frequency, and calculates the average excitation rate based on the statistical excitation results. configured to calculate. The excitation result indicates whether the target qubit was successfully excited or not. Frequency spectral line generation unit 702 is configured to determine frequency spectral lines of the target qubit based on each average excitation rate. The excitation frequency calibration unit 703 is configured to calibrate the target sweep test frequency of the unimodal waveform in the frequency spectrum line as the excitation frequency of the target qubit.

In this embodiment, in the device 700 that calibrates the excitation frequency of a quantum bit, the specific processing of the fluctuation amplitude value pulse excitation unit 701, the frequency spectrum line creation unit 702, and the excitation frequency calibration unit 703 and the technical For the effects, each can refer to the related explanation of steps 201 to 203 in the corresponding embodiment of FIG. 2, and the explanation thereof will be omitted here.

In some optional embodiments of this embodiment, each of the pulse amplitude values is included in a preset sequence of pulse amplitude values at a predetermined pulse length that corresponds to the current sweep test frequency.

In some optional embodiments of this embodiment, each of the pulse amplitude values is arranged by ascending magnitude of the amplitude values in a preset pulse amplitude value sequence.

In some optional embodiments of this embodiment, each of the pulse amplitude values included in the preset pulse amplitude value sequence constitutes an arithmetic progression.

In some optional embodiments of this embodiment, there are N pulse amplitude values in a predetermined sequence of pulse amplitude values, where N is a positive integer greater than or equal to 2.

In some optional embodiments of this embodiment, the magnitude of N corresponding to each different pulse amplitude value is the same.

In some optional embodiments of this embodiment, the excitation pulse includes a π pulse.

In some optional embodiments of this embodiment, the excitation frequency calibration unit 703 further: identifies a unique unimodal waveform in the frequency spectrum line;
A wavelength band higher than a band corresponding to a preset excitation rate in a unimodal waveform is set as an excitation wavelength band,
The target sweep test frequency corresponding to the excitation wavelength band is configured to be calibrated as the excitation frequency range of the target qubit.

In some optional embodiments of the present embodiments, the apparatus 700 for calibrating the excitation frequency of qubits further comprises calibrating the excitation frequency for all target qubits on a quantum chip of a superconducting quantum computer. a marking unit configured to apply a calibration complete mark to the quantum chip in response to the completion of the calibration;
a calculation task execution unit configured to perform a calculation task using the quantum chip to which the calibration completion mark is attached.

This embodiment exists as an embodiment of an apparatus corresponding to the embodiment of the method described above, and the apparatus for calibrating the excitation frequency of a qubit provided by this embodiment is a conventional one for each sweep test frequency in the process of a sweep experiment. The sweep test method, which involves multiple repetitions of testing based only on a fixed pulse amplitude value, is changed to performing a sweep test based on pulses with varying amplitude values, thereby improving the accuracy of the selected fixed pulse amplitude value. By trying each pulse with a different pulse amplitude value, it is possible to obtain a relatively accurate excitation frequency with a relatively small number of tests. It is possible to improve the efficiency of calibration by completing highly accurate calibration of the excitation frequency of multiple qubits by an automated process and method.

According to embodiments of the present disclosure, the present disclosure further provides an electronic device including at least one processor and a memory communicatively connected to the at least one processor, the memory including at least one processor and a memory communicatively connected to the at least one processor. An electronic device in which executable instructions are stored and, when executed by at least one processor, implement a method for calibrating the excitation frequency of a qubit as described in any of the embodiments above in at least one processor. I will provide a.

According to embodiments of the present disclosure, the present disclosure further provides a readable storage medium having computer instructions stored thereon for causing a computer to perform a method of calibrating the excitation frequency of a qubit as described in any of the embodiments above. I will provide a.

According to embodiments of the present disclosure, the present disclosure further provides a computer program product comprising a computer program product that, when executed by a processor, is capable of implementing a method of calibrating the excitation frequency of a qubit as described in any of the embodiments above. Provide products.

FIG. 8 depicts a schematic block diagram of an example electronic device 800 that can be used to implement embodiments of the present disclosure. Electronic equipment refers to various forms of numerical computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic equipment may also represent various forms of mobile devices such as personal digital processing, mobile phones, smart phones, wearable devices, and other similar computing devices. It should be noted that the components shown here, their connection relationships, and their functions are illustrative only and are not intended to limit the embodiments of the present disclosure described and/or requested herein.

As shown in FIG. 8, electronic device 800 can perform various suitable operations according to a computer program stored in read-only memory (ROM) 802 or loaded into random access memory (RAM) 803 from storage unit 808. and a calculation unit 801 capable of executing processing. The RAM 803 can further store various programs and data necessary for the operation of the device 800. Computing unit 801, ROM 802 and RAM 803 are connected to each other via bus 804. An input/output (I/O) interface 805 is also connected to bus 804.

The electronic device 800 includes an input unit 806 such as a keyboard and a mouse, an output unit 807 such as various types of displays and speakers, a storage unit 808 such as a magnetic disk or an optical disk, and a network plug-in, modem, and wireless communication transceiver. A plurality of components, including a communication unit 809 such as, are connected to the I/O interface 805. Communication unit 809 enables electronic device 800 to exchange information or data with other devices via computer networks such as the Internet and/or various telecommunications networks.

Computing unit 801 may be a variety of general-purpose and/or special-purpose processing components with processing and computing capabilities. Some examples of computational units 801 include central processing units (CPUs), graphics processing units (GPUs), various specialized artificial intelligence (AI) computational chips, various computational units that execute machine learning model algorithms, digital including, but not limited to, a signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Computation unit 801 performs various methods and processes, such as the method of calibrating the excitation frequency of the qubits described above. For example, in some embodiments, a method for calibrating the excitation frequency of a qubit may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 808. In some embodiments, some or all of the computer program may be loaded and/or installed on electronic device 800 via ROM 802 and/or communication unit 809. When the computer program is loaded into the RAM 803 and executed by the calculation unit 801, it is possible to perform one or more steps of the method for calibrating the excitation frequency of a qubit as described above. Alternatively, in other embodiments, the calculation unit 801 may be configured to perform the method of calibrating the excitation frequency of the qubit by any other suitable method (e.g., via firmware).

Various embodiments of the systems and techniques described herein include digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), and system onboard systems. It can be implemented in a chip (SOC), a complex programmable logic device (CPLD), computer hardware, firmware, software, and/or a combination thereof. Each of these embodiments is implemented in one or more computer programs that can be executed and/or interpreted in a programmable system that includes at least one programmable processor; may be a dedicated or general purpose programmable processor, and is capable of receiving data and instructions from a storage system, at least one input device and at least one output device, and transmitting data and instructions to the storage system, the at least one output device; The method may include transmitting to an input device and the at least one output device.

Program code for implementing the methods of this disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing device, and when executed by the processor or controller, the flowcharts and/or or the functions or operations specified in the block diagram are implemented. The program code can run completely on the device, partially on the device, or partially on a remote device while running partially on the device as a standalone software package. It can also be run entirely on a remote device or server.

In the context of this disclosure, a machine-readable medium may be a tangible medium and includes a program for use by or in conjunction with a command execution system, device or equipment. or may be stored. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any suitable combination thereof. More specific examples of machine-readable storage media include electrical connections based on one or more cables, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable It may include read only memory (EPROM or flash memory), fiber optics, compact disk read only memory (CD-ROM), optical storage, magnetic storage, or any suitable combination thereof.

To provide user interaction, the systems and techniques described herein include a display device (e.g., a cathode ray tube (CRT) or LCD (liquid crystal display) monitor) and a keyboard for displaying information to the user. and a pointing device (eg, a mouse or trackball) through which a user can provide input to the computer. Other types of devices can also be used to interact with users. For example, the feedback provided to the user may be any form of sensing feedback, e.g., visual, auditory, or haptic feedback, and any form of sensing feedback from the user including audio, audio, or tactile input. may receive input.

The systems and techniques described herein may be implemented on a computing system that includes back-end components (e.g., a data server) or may be implemented on a computing system that includes middleware components (e.g., an application server). , or may be implemented on a computing system (e.g., a user computer having a graphical user interface or web browser) that includes a front-end component, through which the user can access the systems and techniques described herein. or may be implemented in a computing system that includes any combination of such back-end, middleware, or front-end components. Further, the components of the system may be connected by digital data communication via any form or medium such as a communication network. Communication networks include local area networks (LANs), wide area networks (WANs), the Internet, and the like.

A computer system may include a client and a server. Clients and servers are typically remote from each other and interact via a communications network. The relationship between a client and a server is created by running computer programs on their respective computers that have a client-server relationship with each other. The server may be a cloud server, also referred to as a cloud computing server or cloud host, which is a host product in a cloud computing service system, and is a management product in a traditional physical host and virtual private server (VPS, Virtual Private Server) service. This solves the flaws of high difficulty and low business scalability.

According to the technical solution of the embodiments of the present disclosure, for each sweep test frequency in the process of a sweep experiment, the sweep test method of carrying out repeated tests multiple times only based on the conventional fixed pulse amplitude value can be replaced with a sweep test method with varying amplitude values. changed to performing sweep tests based on pulses, thereby avoiding as much as possible the problem of reduced test efficiency due to the low precision of the selected fixed pulse amplitude values, i.e. with different pulse amplitude values. By experimenting with each pulse, a relatively more accurate excitation frequency can be obtained with relatively fewer tests, and by an automated method that completes a highly accurate calibration of the excitation frequency of a multi-qubit. Efficiency can be improved.

It should be understood that the various forms of flow described above can be used and steps can be rearranged, added or deleted. For example, each step described in this disclosure may be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved. It may be executed with The specification is not limited here.

The above specific embodiments do not limit the protection scope of the present disclosure. Those skilled in the art should appreciate that various modifications, combinations, subcombinations, and substitutions may be made depending on design requirements and other factors. All modifications, equivalent replacements, improvements, etc. made without departing from the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims (21)

For each sweep test frequency, the target qubit is excited with excitation pulses having different pulse amplitude values, and the average excitation rate is calculated based on the statistical excitation result indicating whether the target qubit is successfully excited or not. steps to calculate,
determining frequency spectral lines of the target qubit based on each of the average excitation rates;
calibrating a target sweep test frequency of a unimodal waveform in the frequency spectrum line as an excitation frequency of the target qubit;
How to calibrate the excitation frequency of qubits containing 2. The method of claim 1, wherein each of the pulse amplitude values is included in a preset sequence of pulse amplitude values at a predetermined pulse length, corresponding to a current sweep test frequency. 3. The method of claim 2, wherein each of the pulse amplitude values is arranged in ascending order of magnitude in the preset pulse amplitude value sequence. 3. The method of claim 2, wherein each of the pulse amplitude values included in the predetermined sequence of pulse amplitude values constitutes an arithmetic progression. 3. The method of calibrating the excitation frequency of a quantum bit according to claim 2, wherein there are N pulse amplitude values in the preset pulse amplitude value sequence, and N is a positive integer of 2 or more. 6. The method of claim 5, wherein the magnitude of N corresponding to different pulse amplitude values is the same. 2. The method of claim 1, wherein the excitation pulse comprises a π pulse. calibrating a target sweep test frequency of a unimodal waveform in the frequency spectrum line as an excitation frequency of the target qubit;
identifying a unique unimodal waveform in the frequency spectrum line;
setting a wavelength band higher than a band corresponding to a preset excitation rate in the unimodal waveform as an excitation wavelength band;
calibrating a target sweep test frequency corresponding to the excitation wavelength band as an excitation frequency of the target qubit;
A method for calibrating the excitation frequency of a qubit according to any one of claims 1 to 7. Adding a calibration completion mark to the quantum chip in response to completion of excitation frequency calibration for all target qubits on the quantum chip of the superconducting quantum computer;
performing a calculation task using the quantum chip to which the calibration completion mark is attached;
A method for calibrating the excitation frequency of a qubit according to any one of claims 1 to 7, further comprising: For each sweep test frequency, the target qubit is excited with excitation pulses having different pulse amplitude values, and the average excitation rate is calculated based on the statistical excitation result indicating whether the target qubit is successfully excited or not. a varying amplitude value pulse excitation unit configured to calculate;
a frequency spectral line creation unit configured to determine a frequency spectral line of the target qubit based on each of the average excitation rates;
an excitation frequency calibration unit configured to calibrate a target sweep test frequency of a unimodal waveform in the frequency spectrum line as an excitation frequency of the target qubit;
A device for calibrating the excitation frequency of a qubit containing a qubit. 11. The apparatus for calibrating the excitation frequency of a qubit as claimed in claim 10, wherein each of the pulse amplitude values is included in a preset sequence of pulse amplitude values at a predetermined pulse length, corresponding to a current sweep test frequency. 12. The apparatus of claim 11, wherein each of the pulse amplitude values is arranged in ascending order of amplitude value in the preset pulse amplitude value sequence. 12. The apparatus for calibrating the excitation frequency of a qubit according to claim 11, wherein each of the pulse amplitude values included in the preset pulse amplitude value sequence constitutes an arithmetic progression. 12. The apparatus for calibrating the excitation frequency of a quantum bit according to claim 11, wherein there are N pulse amplitude values in the preset pulse amplitude value sequence, and N is a positive integer of 2 or more. 15. The apparatus for calibrating the excitation frequency of a qubit according to claim 14, wherein the magnitude of N corresponding to different pulse amplitude values is the same. 11. The apparatus for calibrating the excitation frequency of a qubit according to claim 10, wherein the excitation pulse includes a π pulse. The excitation frequency calibration unit includes:
identifying a unique unimodal waveform that exists in the frequency spectrum line;
In the unimodal waveform, a wavelength band higher than a band corresponding to a preset excitation rate is set as an excitation wavelength band,
further configured to calibrate a target sweep test frequency corresponding to the excitation wavelength band as an excitation frequency of the target qubit;
Apparatus for calibrating the excitation frequency of a quantum bit according to any one of claims 10 to 16. configured to add a calibration completion mark to the quantum chip in response to completion of excitation frequency calibration for all target qubits on the quantum chip of the superconducting quantum computer; a mark adding unit;
an arithmetic task execution unit configured to execute an arithmetic task using a quantum chip to which the calibration completion mark is attached;
The device for calibrating the excitation frequency of a quantum bit according to any one of claims 10 to 16, further comprising: An electronic device comprising at least one processor and a memory communicably connected to the at least one processor,
The memory stores instructions executable by the at least one processor, and when the instructions are executed by the at least one processor, the at least one processor receives instructions according to any one of claims 1 to 7. An electronic device for performing the described method for calibrating the excitation frequency of a qubit. A non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform the method for calibrating the excitation frequency of a quantum bit according to any one of claims 1 to 7. Computer program, when executed by a processor, implements the method for calibrating the excitation frequency of a qubit according to any one of claims 1 to 7.