Information processing device, sweeping method, and program

Abstract

This information processing device comprises a sweeping unit that executes, in a predetermined sweeping order, sweeping of a plurality of parameters used for controlling pieces of hardware which control quantum bits in a quantum computer.

Description

Information processing device, sweeping method, and program

[0001] The present invention relates to the technical field of quantum computers.

[0002] Quantum computers are a technology that performs calculations by utilizing the principle of superposition in quantum mechanics. If a sufficiently large quantum computer is constructed, it is expected to demonstrate performance far superior to that of currently widely used computers (classical computers) in fundamental computational tasks related to material analysis and the discovery of periodicities, which are areas in which quantum computers excel. For this reason, the development of practical-scale quantum computers is being actively pursued around the world.

[0003] NTT R&D Website, Research & Activities, "Design and Development of Superconducting Quantum Computer Systems," September 8, 2023, https: / / www.rd.ntt / research / JN202309_23089.html, Internet, retrieved May 28, 2024

[0004] In a typical measurement protocol for quantum computers, the intensity and frequency of the microwaves irradiated to observe the spectrum of the measurement target are continuously swept and the response is displayed as a graph (see, for example, Non-Patent Document 1). Some parameters used in experiments can be updated immediately, while others require time to update. Therefore, efficient parameter sweeping is necessary to conduct experiments efficiently.

[0005] The present invention has been made in view of the above points, and has an object to provide a technique for efficiently sweeping parameters in a quantum computer.

[0006] According to the disclosed technology, an information processing device is provided that includes a sweep unit that sweeps a plurality of parameters used to control hardware that controls quantum bits in a quantum computer in a predetermined sweep order.

[0007] The disclosed technology can provide a technology for efficiently sweeping parameters in a quantum computer.

[0008] FIG. 1 is a diagram showing an example of a device configuration common to the first to third embodiments. FIG. 2 is a diagram showing an example of a functional configuration of an information processing device 100 in the first embodiment. FIG. 3 is a flowchart of processing in the first embodiment. FIG. 4 is a diagram showing an example of a functional configuration of an information processing device 100 in the second embodiment. FIG. 5 is a flowchart of processing in the second embodiment. FIG. 6 is a diagram showing an image of a quantum circuit corresponding to a control signal. FIG. 7 is a diagram showing an image of constructing waveforms corresponding to a measurement method and a quantum gate. FIG. 8 is a diagram showing an example of a functional configuration of an information processing device 100 in the third embodiment. FIG. 9 is a diagram for explaining an experiment module and an experiment sequence in the third embodiment. FIG. 10 is a flowchart of processing in the third embodiment. FIG. 11 is a diagram showing an example of a hardware configuration of an information processing device 100.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0010] In the following, first, in order to facilitate understanding of the technology according to this embodiment, a conventional technology relating to a quantum computer that is related to this embodiment will be described.

[0011] [About quantum computing] Quantum computers (which can also be called quantum computers) are a technology that performs calculations by utilizing the principle of superposition in quantum mechanics. If a sufficiently large quantum computer is constructed, it is expected to perform much better than currently widely used computers (classical computers) in basic calculation tasks related to material analysis and the discovery of periodicity, which are areas in which quantum computers excel. For this reason, the development of quantum computers on a practical scale has been actively pursued around the world.

[0012] A (classical) bit, which is an element that makes up a classical computer, takes on a value of 0 or 1. On the other hand, a "qubit," which is an element that makes up a quantum computer, can take on a continuous superposition of 0 and 1 in addition to 0 and 1. By making good use of a property called the interference effect (coherence) that occurs in this superposition state, it is possible to reduce the probability of obtaining an undesired answer in a problem with a periodic structure, making the high-speed calculations described above possible.

[0013] When performing calculations using quantum bits, not only is it necessary to transition the quantum bit from one state to another, but it is also necessary to read out the calculation results in the form of a normal bit string that can be recognized by humans. The operation of extracting a classical bit string from this quantum bit is technically called "measurement" or "observation." When a measurement is performed on a quantum bit that is in a superposition of two states, 0 and 1, the value is probabilistically determined to be 0 or 1 depending on the absolute value squared of the component in the superposition. As a side effect of the measurement, the state of the quantum bit changes depending on the measured value.

[0014] [Quantum Computer Noise and Device Development] The superposition state of a quantum bit is known to be sensitive to environmental noise and easily destroyed in naive implementations. A quantum device refers to a device that can maintain a quantum superposition state for a long period of time and that can be specifically controlled. In particular, superconducting quantum bits created using superconducting circuits have been successfully scaled up to several hundred quantum bits, and are therefore considered one of the standard quantum bits. Typically, a superconducting quantum bit defines the lowest energy state (ground energy state) of the created circuit as 0, and the next lowest energy state as 1.

[0015] To perform calculations using quantum bits, it is necessary to implement an operation that changes the quantum bit to a different state and a measurement that extracts the quantum bit's information as a classical bit. The implemented superconducting quantum bit itself is a passive element, and its operation and measurement are achieved by irradiating it with microwave pulses with a programmed waveform via a transmission line. Note that "operation and measurement" can be collectively called "control." Furthermore, "measurement" can also be called "gauging." Superconducting quantum bits are typically controlled by external irradiation with microwaves with a frequency of several GHz.

[0016] The operation of a quantum bit can be achieved by irradiating it with microwaves of a specific envelope whose carrier frequency is the quantum bit's resonant frequency. For measurement, a technique called distributed readout is currently commonly used. Instead of irradiating the quantum bit directly with a signal, this technique excites a resonator with the appropriate resonant frequency coupled to the quantum bit from an external source, and indirectly probes the quantum bit's state from the reflection of the excited signal.

[0017] [Signal Creation] To control a quantum bit programmably, it is necessary to construct a pulse signal generation system that uses the resonant frequency of the superconducting quantum bit as a carrier frequency and allows for designing the envelope shape. Because it is difficult to directly generate the arbitrary waveforms in the several GHz band required by superconducting quantum bits using a typical waveform generator, the signal is generated by combining a low-frequency arbitrary waveform generator with a signal source that outputs a high-frequency sine wave using a mixer and filtering the combined signals. Receiving a signal to read the quantum bit is achieved by following the reverse procedure and converting the received analog signal into a digital signal. Because the above procedure is implemented independently for each quantum bit to be controlled, the number of ports on the control device required increases in proportion to the number of quantum bits.

[0018] [Qubit Calibration] The superconducting circuits that make up superconducting qubits have a certain degree of variability each time they are manufactured. Therefore, when evaluating them, repeated test measurements must be performed to clarify their characteristics and create optimal pulse waveforms for control. In this process, learning the qubit's characteristics is called qubit characterization, and the process of calibrating the qubit-controlling pulses based on this information is called qubit calibration. Identifying qubit characteristics from an unknown state and then designing signals to achieve the desired qubit control based on these characteristics is a highly nonlinear optimization process, and a fast, stable, and accurate method for achieving this is not obvious. While several standard calibration techniques exist, no established prior art exists. Furthermore, performing this task manually requires a long time proportional to the number of qubits, making it impractical. For these reasons, a fast and automatic calibration method is necessary for the development and realization of quantum computers.

[0019] (Outline of the Embodiments) In this specification, the following first, second, and third embodiments will be described. The outline of each embodiment is as follows.

[0020] The first embodiment is an embodiment of a mechanism that enables various devices to be freely combined and controlled using an abstracted common interface.

[0021] The second embodiment is an embodiment of a function that enables parameters to be freely swept during an experiment, and that enables experimental data to be managed, saved, and reproduced in a fixed format.

[0022] The third embodiment is an embodiment of a mechanism for characterizing and calibrating qubits while updating parameters.

[0023] (Overall Configuration Diagram) First, an example of the overall device configuration common to the first, second, and third embodiments is shown in Fig. 1. The configuration shown in Fig. 1 (excluding the user terminal 30) is called a quantum computer. The configuration shown in Fig. 1 (excluding the user terminal 30) may also be called a quantum computing device or a quantum computing system.

[0024] 1, the quantum computer in this embodiment includes quantum hardware 10, a plurality of electronics 20, and an information processing device 100. In this embodiment, a user terminal 30 accesses the information processing device 100 to perform a desired quantum computation or experiment.

[0025] The quantum hardware 10 in this embodiment includes the integrated quantum bit and the entire system inside the dilution refrigerator. More specifically, the quantum hardware 10 in this embodiment includes the readout resonator connected to the quantum bit, peripheral circuits such as the JPA, the dilution refrigerator, and the coaxial cable connecting the dilution refrigerator to the room temperature environment, amplifiers, attenuators, etc. Note that this embodiment assumes that the above-mentioned superconducting quantum bit is used as the quantum bit. However, the technology according to the present invention can also be applied to quantum bits other than superconducting quantum bits.

[0026] The multiple electronics 20 are a series of hardware for controlling the quantum bits. Examples of hardware for generating and shaping pulses for controlling quantum bits include a frequency source, an arbitrary waveform generator, a network analyzer, a variable resistor, a constant current source, a mixer, and an analog-to-digital converter. Of these, the frequency source and arbitrary waveform generator have already been described. A device combining an arbitrary waveform generator and an analog-to-digital converter may also be used. Alternatively, a device combining an arbitrary waveform generator, an analog-to-digital converter, a mixer, and a frequency source may also be used. The constant current source and variable resistor are devices that can specify an externally applied current value and attenuation rate. The analog-to-digital converter is a device that converts a received analog signal into a digital signal. The network analyzer is a device capable of measuring in both the frequency domain and the time domain. In frequency domain measurements, signal characteristics (S11, S12, S21, S22) are evaluated while switching between certain frequency domains at equal intervals.

[0027] The information processing device 100 executes a program (software) to perform the processes described in the first to third embodiments described below. Note that the information processing device 100 may have only the functions corresponding to one of the first to third embodiments, or only the functions corresponding to two of the first to third embodiments. Each embodiment will be described below. In each of the following embodiments, unless otherwise specified or unless it is clear from the context that a different meaning is intended, a "parameter" means "a parameter name and its value" (e.g., a frequency of 10 GHz). A "parameter" may also be used to mean "a set of parameters."

[0028] (First Embodiment) <Regarding Issues in the First Embodiment> As described above, measurement and control in a quantum computer require a variety of devices, such as an arbitrary waveform generator and a mixer, and a mechanism for controlling these devices in an integrated manner is required. Meanwhile, because the technology of the hardware (the electronics described above) that controls quantum computers and the technology of the control method for the quantum bits themselves are continuously evolving, software and technology that are closely related to the infrastructure of a specific control device must be reimplemented when the underlying technology changes, making development inefficient.

[0029] Therefore, to efficiently implement a quantum computer, a mechanism is needed to abstract the control of the device and enable the use of higher-level software with almost no changes.

[0030] In the first embodiment, a control technique that abstracts hardware and is robust against hardware changes in controlling a quantum computer using microwaves will be described.

[0031] <Configuration and Operation in First Embodiment> Fig. 2 shows an example of the functional configuration of an information processing device 100 in the first embodiment. The "hardware" shown in Fig. 2 corresponds to the electronics shown in Fig. 1. The "hardware" may also be called an experimental device.

[0032] In the first embodiment, the information processing device 100 abstracts control of hardware into two layers, a first layer and a second layer. To achieve this, the information processing device 100 includes a first-layer parameter storage unit 110, a second-layer parameter storage unit 120, and a conversion unit 130.

[0033] The first-layer parameter storage unit 110 stores first-layer parameters, which are parameters that abstract the parameters of the hardware. The first-layer parameters stored in the first-layer parameter storage unit 110 are parameters whose contents can be intuitively understood by a user. For example, if the hardware is a frequency source, the first-layer parameter storage unit 110 stores the frequency and its intensity input from the user terminal 30. Furthermore, if the hardware is an attenuator, the first-layer parameter storage unit 110 stores the attenuation rate and the like input from the user terminal 30 as parameters.

[0034] The conversion unit 130 converts the first-layer parameters into second-layer parameters, which are parameters directly linked to hardware. The second-layer parameters are parameters related to the control of quantum bits. For example, if control of hardware A and hardware B is required to achieve control using the first-layer parameters, the conversion unit 130 converts the first-layer parameters into parameters of hardware A and hardware B.

[0035] The second-layer parameter storage unit 120 stores second-layer parameters. The second-layer parameter storage unit 120 may include a function for performing experiments such as measurements by controlling hardware using the second-layer parameters.

[0036] For example, a user describes first-layer parameters in the form of a frequency and a control pulse shape for the i-th quantum bit to the first-layer parameter storage unit 110 from the user terminal 30. That is, the user describes the experiment details for the quantum bit using the parameters in the first-layer parameter storage unit 110. Then, the conversion unit 130 converts the first-layer parameters into second-layer parameters. The converted second-layer parameters are used to control the hardware.

[0037] Furthermore, when the first-layer parameter storage unit 110 stores first-layer parameters and the second-layer parameter storage unit 120 stores second-layer parameters linked to the first-layer parameters, if the user instructs the information processing device 100 (specifically, the conversion unit 130) to update the first-layer parameters, the second-layer parameters linked to the first-layer parameters are also updated.

[0038] A flowchart of the above process is shown in Fig. 3. In S101, the name of the parameter of the first layer to be changed and the parameter after the change are input from the user terminal 30 to the information processing device 100.

[0039] In S102, the conversion unit 130 updates the second-layer parameters linked to the first-layer parameters. That is, the conversion unit 130 adjusts (or translates) the update content of the second-layer parameters so that the second-layer parameters are updated as desired.

[0040] <Effects of the First Embodiment> The technology according to the first embodiment enables flexible implementation in response to replacement of hardware functions and performance, thereby improving the efficiency of measurement and control of a quantum computer. For example, even if new hardware is installed and the method for inputting values ​​into the hardware changes, the modification can be made by changing the processing content in the conversion unit 130 without affecting other parts of the quantum computer.

[0041] Furthermore, if the constraints on the second-layer parameters or the types of the parameters themselves change, by updating the processing content of the conversion unit 130 (specifically, software) that converts the first-layer parameters into second-layer parameters, it is possible to use past assets and hardware without affecting other parts.

[0042] Second Embodiment Next, a second embodiment will be described.

[0043] <Regarding the Issues in the Second Embodiment> In a typical measurement protocol, an operation is often performed in which the intensity and frequency of microwaves irradiated are continuously swept to observe the spectrum of a measurement target, and the response is displayed as a graph. Note that sweeping refers to performing an experiment while changing parameters. Sweeping can also be referred to as "sweeping."

[0044] In this embodiment, the sweep may be performed independently for two parameters, or may be performed synchronously for two parameters. Some parameters used in experiments can be updated instantly, while others require time to update. Unless there are special circumstances, it is desirable to perform the sweep of these parameters in the most efficient manner possible in order to efficiently conduct experiments. It is also desirable to save the parameter sweep method together with the experimental data in the form of configuration (setting information) so that it can be reloaded later.

[0045] <Configuration and Operation of Second Embodiment> The second embodiment is premised on the use of the technology according to the first embodiment, and is capable of handling abstracted parameters (parameters that are intuitive to the user). Note that the technology according to the second embodiment may be implemented independently of the first embodiment.

[0046] 4 shows an example of the functional configuration of the information processing apparatus 100 according to the second embodiment. As shown in FIG. 4, the information processing apparatus 100 according to the second embodiment includes a sweep unit 210 and a database unit 220.

[0047] The sweep unit 210 holds a plurality of parameters and performs a sweep on the plurality of parameters. The sweep unit 210 actually communicates with hardware in accordance with the swept parameters and performs measurements using the hardware. Note that the function of communicating with the hardware and performing measurements using the hardware may be external to the sweep unit 210. Here, "sweep" is used to mean performing measurements (which may also be called experiments), but it may also mean not performing measurements.

[0048] The sweep unit 210 holds a plurality of parameters input from, for example, the user terminal 30, and holds, for each parameter, the speed required for sweeping (measurement) or the priority of use. Note that Fig. 4 shows that the sweep unit 210 holds a set of parameters with the parameter name Parameter A and a set of parameters with the parameter name Parameter B.

[0049] When the sweep unit 210 sweeps parameters, there are two sweep modes (first mode and second mode). In the first mode, the sweep unit 210 automatically determines the sweep order to specify the parameters to be used in measurement. In the first mode, the sweep unit 210 automatically determines the order of the parameters to be used in measurement so that the sweep of the specified parameter set can be performed as quickly as possible.

[0050] The time it takes for a parameter to be changed and for the state to stabilize after the change (the time it takes to update) differs depending on the hardware. Therefore, in the first mode, the sweep unit 210 assigns parameters that take a short time to update to deep loops that are updated frequently, and assigns parameters that take a long time to update to shallow loops, thereby reducing the total execution time. Specific examples of "deep loops" and "shallow loops" will be described later.

[0051] The second mode is a mode in which the user specifies the sweeping order to the sweeping unit 210. In this case, the sweeping unit 210 sweeps the parameters in the order specified by the user (user terminal 30).

[0052] When the measurement using the swept parameters is completed, the sweep unit 210 stores the measurement information obtained from the measurement, the parameters used in the measurement, and the execution order (sweep order) linked to an ID as measurement data in the database unit 220. For example, the sweep unit 210 can specify an ID and read out the parameters and sweep order used in a previous measurement from the database unit 220, thereby performing the same measurement again as in the previous measurement.

[0053] <Processing Flow> The processing of the sweeping unit 210 in the second embodiment will be described with reference to the flowchart shown in FIG.

[0054] At the start of processing, a list of pairs of "'Name of parameter to be swept' and 'List of parameters to be swept'" is input to the sweeping unit 210.

[0055] An example of a list of pairs of "parameter name to be swept" and "list of parameters to be swept" is ((parameter A, [10 dB, 20 dB]), (parameter B, [10 GHz, 10.1 GHz, 10.3 GHz])).

[0056] 5, the sweep unit 210 determines whether the parameter sweep order has been designated by the user. If the parameter sweep order has been designated by the user, the process proceeds to S202. If the parameter sweep order has not been designated by the user, the process proceeds to S203.

[0057] In S202, the sweeping unit 210 creates an iterator for the parameters to be updated in the order specified by the user. An "iterator" is a program (object) for obtaining parameters in a parameter set one by one in the specified order. Note that the use of an "iterator" is merely an example. Any method may be used as long as it allows the parameters to be specified so as to speed up the sweeping.

[0058] In S203, if the result in S201 is No, the sweep unit 210 lists the sweep speeds of the parameters to be swept and sorts them in order of sweep. Here, the "sweep speed" of a parameter is, for example, the time from when the parameter is specified in the hardware to when actual measurement using the parameter becomes possible.

[0059] In S204, the sweeping unit 210 rearranges the order of the parameters so that the parameters with faster sweep speeds are inside the loop, and creates an iterator for the parameters to be updated.

[0060] For example, when measurements are performed for all combinations of parameters A and B, suppose that parameters A include parameters A_1, A_2, and A_3, and parameters B_1, B_2, and B_3 as parameters B. Also, suppose that the sweep speed of parameter A is faster than that of parameter B.

[0061] At this time, a loop for parameter A_i (i = 1 to 3) is placed inside a loop for parameter B_j (j = 1 to 3). As a result, for example, parameter A is changed three times, such as parameter A_1 -> parameter A_2 -> parameter A_3 -> parameter A_1, before parameter B_1 is changed to parameter B_2.

[0062] In S205, the sweep unit 210 performs measurement by sweeping the parameters using the iterator created in S202 or S204.

[0063] In S206, the sweep unit 210 stores the measurement information and the parameter sweep order together as measurement data in the database unit 220.

[0064] Here, a specific example of S204 will be described. Suppose the input list is ((parameter A, [0, 1, 2]), (parameter B, [2, 4, 6])). In this embodiment, if there are n types of parameters to be swept, n-axis sweeping is performed. In the above example, there are two types, parameter A and parameter B. Therefore, in the above case, measurement is performed using 3 x 3 = 9 patterns.

[0065] If parameter B has a faster sweep speed than parameter A, the sweep order will be [0,2], [0,4], [0,6], [1,2], [1,4], [1,6], [2,2], [2,4], [2,6]. If parameter A has a faster sweep speed than parameter B, the sweep order will be [0,2], [1,2], [2,2], [0,4], [1,4], [2,4], [0,6], [1,6], [2,6].

[0066] <Effects of the Second Embodiment> The second embodiment allows parameter sweeping to be performed in the most efficient manner without examining the details of specific parameters. Furthermore, if the order of parameter sweeping needs to be specified for some reason, or multiple parameters need to be swept synchronously, this can be done by user specification. Furthermore, the sweeping procedure is stored in the database unit 220 as an experimental procedure together with measurement information, making it possible to reproduce a similar experiment later.

[0067] Third Embodiment Next, a third embodiment will be described.

[0068] <Basic Technology and Issues in the Third Embodiment> As described above, the superconducting quantum bit assumed for use in this embodiment is controlled by irradiating it with a microwave having a shape corresponding to the control content as a control signal. On the other hand, the execution job of a typical quantum computer is expressed as a quantum circuit. An image of how a quantum circuit corresponds to a control signal is shown in FIG. 6. Also, an image of constructing a waveform corresponding to a measurement method and a quantum gate is shown in FIG. 7.

[0069] Any quantum circuit can be described by a combination of four types of operations called "arbitrary angle Z rotation," "90-degree ZX rotation," "90-degree X rotation," and "Z measurement." Of these, "arbitrary angle Z rotation" is a special operation that can be performed without manipulating the quantum bits, so it is necessary to optimize the microwave shapes that correspond to the remaining "90-degree ZX rotation," "90-degree X rotation," and "Z measurement." To calibrate many quantum bits quickly, the information processing device 100 needs to perform this process as efficiently as possible.

[0070] <Configuration and Operation in Third Embodiment> Fig. 8 shows an example of the functional configuration of the information processing device 100 in the third embodiment. As shown in Fig. 8, the information processing device 100 in the third embodiment has an experiment control unit 300, a measurement unit 310, an analysis unit 320, an input parameter holding unit 330, and an output parameter holding unit 340.

[0071] The measurement unit 310 communicates with hardware using input parameters to perform measurements on quantum bits. The measurement unit 310 can perform measurements using the parameter processing technique described in the first embodiment and the sweep technique described in the second embodiment.

[0072] The analysis unit 320 analyzes the output parameters by fitting or the like based on the measurement results obtained by the measurement unit 310 .

[0073] The input parameter storage unit 330 stores a set of input parameters, which are a set of known parameters for carrying out a desired experiment. The output parameter storage unit 330 stores output parameters, which are parameters obtained as a result of the experiment.

[0074] The experiment control unit 300 configures an "experiment module" by utilizing the functions of the measurement unit 310 and the analysis unit 320. A calibration sequence is constructed by a plurality of experiment modules.

[0075] The operation of one experiment module will be described with reference to Fig. 9(a). The experiment module requests input parameters as known information, creates a plan based on the input parameters, and performs measurements (experiments). Specifically, as shown in Fig. 9(a), for example, experimental data is obtained by sweeping the frequency and intensity based on the input parameters and performing measurements.

[0076] Next, the experiment module performs analysis (fitting, etc.) on the experimental data and obtains output parameters as knowledge as a result of the analysis. Note that the experiment module is configured in an abstract form, separate from the implementation of a specific device, and is therefore configured using the techniques of the first and second embodiments.

[0077] The experiment control unit 200 manages an experiment sequence (which may also be called a calibration sequence) consisting of multiple experiment modules. "Manage" may mean that the experiment control unit 200 generates and stores an experiment sequence, or that the experiment control unit 200 stores an experiment sequence input from outside. The input and output parameters in the stored experiment sequence may be values ​​obtained in past experiments, or may be values ​​specified from outside. By executing the path described below, the person performing the calibration obtains the desired output parameters (highly accurate values, etc.).

[0078] As shown in Figure 9(c), the experiment sequence is configured as a directed graph with experiment modules as nodes. This directed graph has a single root node. In Figure 9(c), each node represented by a square is an experiment module. The circles in Figure 9(c) indicate output parameters / input parameters. In other words, the circles upstream of a certain experiment module are input parameters of that experiment module, and the circles downstream of that experiment module are output parameters of that experiment module.

[0079] More specifically, in an experiment sequence, as shown in Fig. 9(b), the input parameters of a certain experiment module (experiment module indicated by A) in the graph are a subset of the union of the output parameters obtained by the experiment module corresponding to its parent node (experiment module indicated by B). For example, if the output parameters (set) are {1, 2, 3} and {2, 3, 4, 5}, the union is {1, 2, 3, 4, 5}, and an example of the subset is {2, 3, 4}.

[0080] When performing calibration, the executive control unit 200 searches the experiment sequence for a path that will determine the target parameters with the fewest number of experiments, and performs measurements (experiments) using the experiment modules on the path in order from the root node. The executive control unit 200 can also search for a path that will allow multiple experiments to be performed in parallel as much as possible.

[0081] The experiment control unit 200 can obtain the desired value of the initially specified parameter name as an output parameter by executing measurements (experiments) using the experiment modules on the above-mentioned path.

[0082] More specifically, the experiment control unit 200 acquires, as output parameters, the microwave shapes corresponding to the aforementioned "90-degree ZX rotation," "90-degree X rotation," and "Z measurement" operations, and in the case of measurement, acquires, as output parameters, information on the method for identifying the readout signal. This allows the basic operations into which a given quantum circuit is decomposed to be individually replaced with microwave shapes.

[0083] <Processing Flow> The processing of the information processing device 100 in the third embodiment will be described with reference to the flowcharts shown in Figures 10 and 11. First, the processing flow of the experiment module will be described with reference to Figure 10. The following processing is the processing of a certain experiment module in an experiment sequence.

[0084] As a prerequisite for processing, a set of parameters (input parameters) relating to the quantum bits currently obtained through experiments is input as input data to the experimental module.

[0085] In S301, the experiment module determines whether all input data is known. If the determination result is Yes, the process proceeds to S302, and if the determination result is No, the process proceeds to S306. In S306, the experiment module outputs an error and ends the process.

[0086] In S302, the experiment module creates parameter sweep information based on the input data, and in S303, the experiment module performs measurements based on the sweep information created in S302 and acquires measurement data.

[0087] In S304, the experiment module performs analysis using the measurement data and input data to acquire knowledge about the quantum bit. In S305, the experiment module updates the set of parameters obtained about the quantum bit. The updated parameters are output parameters.

[0088] Next, the processing flow of the experiment control unit 200 will be described with reference to the flowchart in Figure 11. As a prerequisite for the processing flow, the experiment control unit 200 is input with information that is desired to be obtained as the result of the experiment.

[0089] In S311, the experiment control unit 200 lists one or more experiment modules from the experiment sequence that have the desired information as an output parameter. For example, if the desired information is included in the output parameter C (parameter set) of the experiment module indicated by A in Figure 9(b), the experiment module indicated by A will be one of the experiment modules listed in S311.

[0090] In S312, the experiment control unit 200 searches for the shortest path from the root node to any one of the one or more experiment modules listed. For example, if the experiment module in question is node 3, the root node is node 0, and the shortest path from node 0 to node 3 is "node 0 -> node 2 -> node 5 -> node 3," the search in S312 will obtain this path information: "node 0 -> node 2 -> node 5 -> node 3."

[0091] In S313, the experiment control unit 200 executes each experiment module in the shortest path obtained in S312 in the order of the path, starting from the experiment module at the root node.

[0092] In S314, the experiment control unit 200 obtains the information that was desired at the start as the execution result of the last experiment module.

[0093] <Effects of the Third Embodiment> The technology according to the third embodiment makes it possible to design a sequence for calibrating quantum bits in an extensible manner and to automatically obtain information required for executing a quantum circuit.

[0094] (Hardware Configuration Example) The information processing device 100 described in this embodiment can be realized, for example, by causing a computer to execute a program. This computer may be a physical computer or a virtual machine on the cloud.

[0095] That is, the information processing device 100 can be realized by using hardware resources such as a CPU and memory built into a computer to execute a program corresponding to the processing performed by the information processing device 100. The program can be recorded on a computer-readable recording medium (such as a portable memory) and can be saved or distributed. The program can also be provided via a network such as the Internet or email.

[0096] Fig. 12 is a diagram showing an example of the hardware configuration of the computer. The computer in Fig. 12 includes a drive device 1000, an auxiliary storage device 1002, a memory device 1003, a CPU 1004, an interface device 1005, a display device 1006, an input device 1007, an output device 1008, and the like, all of which are interconnected via a bus B. The computer may further include a GPU.

[0097] The program that realizes the processing on the computer is provided by a recording medium 1001, such as a CD-ROM or a memory card. When the recording medium 1001 storing the program is set in the drive device 1000, the program is installed from the recording medium 1001 to the auxiliary storage device 1002 via the drive device 1000. However, the program does not necessarily have to be installed from the recording medium 1001, but may be downloaded from another computer via a network. The auxiliary storage device 1002 stores the installed program as well as necessary files, data, etc.

[0098] The memory device 1003 reads and stores a program from the auxiliary storage device 1002 when an instruction to start the program is received. The CPU 1004 realizes functions related to the information processing device 100 in accordance with the program stored in the memory device 1003. The interface device 1005 is used as an interface for connecting to a network, etc. The display device 1006 displays a GUI (Graphical User Interface) or the like according to the program. The input device 1007 is composed of a keyboard, mouse, buttons, a touch panel, etc., and is used to input various operation instructions. The output device 1008 outputs the results of calculations.

[0099] Regarding the above embodiment, the following Supplementary Notes 1 to 3 are further disclosed.

[0100] <Supplementary Note 1> (Supplementary Item 1) An information processing device comprising: a first-layer parameter storage unit for storing first-layer parameters; a second-layer parameter storage unit for storing second-layer parameters linked to hardware that controls quantum bits in a quantum computer; and a conversion unit for converting the first-layer parameters to the second-layer parameters. (Supplementary Item 2) The information processing device according to Supplementary Item 1, wherein, when a parameter name to be updated is input to the information processing device from a user terminal, the conversion unit updates the second-layer parameters linked to the first-layer parameters of the parameter name. (Supplementary Item 3) A parameter conversion method executed by an information processing device, wherein the information processing device comprises: a first-layer parameter storage unit for storing first-layer parameters; and a second-layer parameter storage unit for storing second-layer parameters linked to hardware that controls quantum bits in a quantum computer, and the parameter conversion method comprises a conversion step of converting the first-layer parameters to the second-layer parameters. (Supplementary Item 4) A non-transitory storage medium storing a program for causing a computer to function as each unit in the information processing device according to Supplementary Item 1 or 2.

[0101] <Supplementary Item 2> (Supplementary Item 1) An information processing device comprising a sweep unit that sweeps multiple parameters used to control hardware that controls quantum bits in a quantum computer, in accordance with a predetermined sweep order. (Supplementary Item 2) The information processing device according to Supplementary Item 1, wherein the sweep unit determines the predetermined sweep order so that the sweep of the multiple parameters is fast. (Supplementary Item 3) The information processing device according to Supplementary Item 2, wherein, when sweeping combinations of parameters in a first parameter set and parameters in a second parameter set, the sweep unit determines the predetermined sweep order so that a parameter set with a shorter update time is changed more frequently. (Supplementary Item 4) The information processing device according to Supplementary Item 1, wherein the sweep unit determines the predetermined sweep order in accordance with a user specification. (Supplementary Item 5) The information processing device according to Supplementary Item 1, wherein the sweep unit collectively stores the predetermined sweep order and measurement information obtained by performing the sweep in the predetermined sweep order as measurement data in a database. (Supplementary Item 6) A sweeping method executed by an information processing device, comprising: a sweeping step of sweeping a plurality of parameters used to control hardware that controls quantum bits in a quantum computer in a predetermined sweep order. (Supplementary Item 7) A non-transitory storage medium storing a program for causing a computer to function as the sweeping unit in the information processing device according to any one of Supplementary Items 1 to 5.

[0102] <Supplementary Item 3> (Supplementary Item 1) An information processing device comprising: an experiment control unit that calibrates a quantum bit in a quantum computer by sequentially causing each of a plurality of experiment modules, each having a measurement function and an analysis function, to perform measurement and analysis on each of the plurality of experiment modules arranged on a predetermined path. (Supplementary Item 2) The information processing device according to Supplementary Item 1, wherein the experiment control unit determines the predetermined path as the shortest path from a root node to a node having a desired output parameter in a directed graph having experiment modules as nodes. (Supplementary Item 3) A quantum bit calibration method executed by an information processing device, comprising: calibrating a quantum bit in a quantum computer by sequentially causing each of a plurality of experiment modules, each having a measurement function and an analysis function, to perform measurement and analysis on each of the plurality of experiment modules arranged on a predetermined path. (Supplementary Item 4) A non-transitory storage medium storing a program for causing a computer to function as the information processing device according to Supplementary Item 1 or 2.

[0103] Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0104] 10 Quantum hardware 20 Electronics 30 User terminal 100 Information processing device 110 First layer parameter storage unit 120 Second layer parameter storage unit 130 Conversion unit 210 Sweep unit 220 Database unit 300 Experiment control unit 310 Measurement unit 320 Analysis unit 330 Input parameter storage unit 340 Output parameter storage unit 1000 Drive device 1001 Recording medium 1002 Auxiliary storage device 1003 Memory device 1004 CPU 1005 Interface device 1006 Display device 1007 Input device 1008 Output device

Claims

1. An information processing device comprising a sweep unit that sweeps a plurality of parameters used to control hardware that controls quantum bits in a quantum computer in a predetermined sweep order.

2. The information processing device according to claim 1, wherein the sweeping unit determines the predetermined sweeping order so that the sweeping of the plurality of parameters is performed at high speed.

3. The information processing device according to claim 2, wherein the sweeping unit determines the predetermined sweeping order so that, when sweeping combinations of each parameter in the first parameter set and each parameter in the second parameter set, a parameter set with a shorter update time is changed more frequently.

4. The information processing device according to claim 1, wherein the sweeping unit determines the predetermined sweeping order in accordance with a user's instruction.

5. The information processing device according to claim 1, wherein the sweeping unit stores the predetermined sweeping sequence and measurement information obtained by performing the sweeping in the predetermined sweeping sequence together as measurement data in a database.

6. A sweeping method executed by an information processing device, comprising a sweeping step of sweeping a plurality of parameters used to control hardware that controls quantum bits in a quantum computer in a predetermined sweep order.

7. A program for causing a computer to function as a sweeping unit in the information processing device according to any one of claims 1 to 5.

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