Quantum circuit, quantum computing element, quantum computing system, and quantum computing method

Abstract

Provided are a quantum circuit, a quantum computing element, a quantum computing system, and a quantum computing method, which are capable of physical reservoir computing with high learning efficiency. A quantum circuit 100 comprises a plurality of superconducting lines 101, 102, 103, 104 that form quantum bits depending on an electromagnetic state, and that interact with each other, a plurality of lines L11, L12, L13, L14 electromagnetically connected to the plurality of superconducting lines 101, 102, 103, 104, respectively, a plurality of lines L21, L22, L23, L24 electromagnetically connected to plurality of superconducting lines 101, 102, 103, 104, respectively, and a plurality of read circuits R1, R2, R3, R4 electromagnetically connected to the plurality of superconducting lines, respectively, each first line is configured so as to be capable of receiving an input signal individually, and each reading circuit is configured so as to be capable of outputting a read signal based on the state of the quantum bit of the corresponding superconducting line.

Description

[Technical field]

[0001] The present invention relates to a quantum circuit, a quantum computing element, a quantum computing system, and a quantum computing method. [Background technology]

[0002] One machine learning technique is reservoir computing, which uses a neural network with an input layer, a reservoir layer, and an output layer. The reservoir layer in reservoir computing is a recurrent neural network with random connections. In other words, the reservoir layer is a network circuit that responds nonlinearly.

[0003] There are devices for physically implementing a reservoir layer by hardware, not by software operation. Such devices are called physical reservoir devices, for example, in Non-Patent Document 1. Non-Patent Document 1 shows that a reservoir layer can be constructed by physical phenomena in a laser-based or spin-based physical reservoir device. In this way, reservoir computing that is performed by constructing a reservoir layer by a physical reservoir device is called physical reservoir computing.

[0004] In physical reservoir computing, a continuous signal is input to the input layer, and a continuous signal is output from the output layer through a nonlinear response in the reservoir layer. Learning in physical reservoir computing is performed by discretizing the input signal and the read signal from the output layer, and updating the weights of the linear combination between the reservoir layer and the output layer so as to correct the value of the discretized signal. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Satoshi Yamane, "Machine learning devices using physical reservoir computing and their application to edge computing", Provision, IBM Japan, 2019, No. 95, pp. 57-61 Summary of the Invention [Problem to be solved by the invention]

[0006] To improve the learning efficiency in physical reservoir computing, it is preferable that the reservoir layer is a dynamical system with high nonlinearity. To increase the nonlinearity, it is preferable that the degree of freedom of the dynamical system is high. Although there are various cases where a single element (1 bit) capable of constituting a physical reservoir can operate, it is difficult to realize a physical reservoir that makes multiple elements work together in an orderly manner. When it is difficult to make multiple elements work together, the degree of freedom of the dynamical system is limited, making it difficult to improve the learning efficiency in physical reservoir computing.

[0007] Therefore, an object of the present invention is to provide a quantum circuit, a quantum computing element, a quantum computing system, and a quantum computing method that enable physical reservoir computing with high learning efficiency. [Means for solving the problem]

[0008] A quantum circuit according to one embodiment of the present invention comprises a plurality of superconducting lines which form quantum bits based on their electromagnetic states and which interact with each other, a plurality of first lines which are electromagnetically coupled to each of the plurality of superconducting lines, each of which is configured to be able to individually receive an input signal, a plurality of second lines which are electromagnetically coupled to each of the plurality of superconducting lines, and a plurality of readout circuits which are electromagnetically coupled to each of the plurality of superconducting lines, each of which is configured to be able to output a readout signal based on the state of the quantum bit of a corresponding superconducting line.

[0009] According to this aspect, an input signal is input to each first line individually. Based on the input signal, each first line controls the state of the quantum bit of the corresponding superconducting line. The state of the quantum bit of each superconducting line changes due to the interaction of each superconducting line. The read signal from the read circuit is a signal based on the state of the quantum bit of the superconducting line that has changed based on the input signal. The read signal is not a signal resulting from superimposing the input signals, but a nonlinear signal. In the quantum circuit, since the input signal is input to each first line individually, the degree of freedom in the quantum circuit as a physical reservoir device can be increased by associating the input signal with each of a plurality of parameters. In the physical reservoir computing using the quantum circuit of the above aspect, the degree of freedom can be increased to increase the nonlinearity. Therefore, the quantum circuit enables physical reservoir computing with high learning efficiency.

[0010] A quantum computing device according to another aspect of the present invention includes the quantum circuit of the above aspect. According to this, the quantum computing device enables physical reservoir computing with high learning efficiency.

[0011] In the above aspect, the quantum computing device may further include a quantum circuit different from the quantum circuit of the above aspect. In this way, the quantum computing device can be an element that can handle a plurality of computing purposes by switching between the quantum circuit of the above aspect and the different quantum circuit according to the computing purpose.

[0012] A quantum computing system according to another aspect of the present invention includes the quantum computing device of the above aspect, and a control device configured to supply an input signal to the quantum computing device and obtain a read signal from the quantum computing device, whereby physical reservoir computing is controlled by the control device, enabling physical reservoir computing with high learning efficiency.

[0013] The quantum computing system of the above aspect may further include a signal generating device communicatively connected to the control device and configured to generate a first signal, and the control device may be configured to supply an input signal based on the first signal to the quantum computing device. In this way, when the signal generating device supplies a signal based on a signal from a device such as a sensor to the quantum computing device, for example, physical reservoir computing that performs learning and inference using a signal from a device such as a sensor located on the edge side of the system is possible.

[0014] In the quantum computing system of the above aspect, the quantum computing element is a first quantum computing element, the control device is a first control device, and the quantum computing system may further include a second quantum computing element, a second control device configured to control the computation in the second quantum computing element, and a computation management device communicatively connected to the first control device and the second control device and configured to supply an element selection signal indicating the quantum computing element performing the quantum computation to the first control device or the second control device.

[0015] By supplying an element selection signal so that the computation management device selects a quantum computing element according to the content of the computation process, the quantum computing system becomes a system capable of utilizing computation results from a plurality of quantum computing elements.

[0016] A quantum computing method according to another aspect of the present invention includes: supplying an input signal to each of a plurality of first lines that are electromagnetically coupled to each of a plurality of superconducting lines that configure a quantum bit by an electromagnetic state; and outputting a readout signal from each of a plurality of readout circuits that are electromagnetically coupled to each of the plurality of superconducting lines based on the state of the quantum bit of the corresponding superconducting line. This enables physical reservoir computing with high learning efficiency, similar to the quantum circuit of the above aspect.

[0017] In the quantum computing method of the above aspect, outputting the read signal may include outputting the read signal that is a continuous signal. When the read signal is output as a continuous signal, the input signal and the read signal are discretized and learning is performed based on the value of the discretized signal, which enables physical reservoir computing.

[0018] In the quantum computing method of the above aspect, the input signal may be individually supplied to each of the first lines, the number of which is less than the number of the readout circuits that output the readout signal. This enables physical reservoir computing using a delay network type physical reservoir unit.

[0019] In the quantum computing method of the above aspect, the input signal may be individually supplied to each of the first lines, the number of which is greater than the number of the readout circuits that output the readout signal. This enables physical reservoir computing using a continuous medium type physical reservoir unit.

[0020] In the quantum computing method of the above aspect, the input signal is supplied individually to each first line, and may include supplying the input signal to each first line at a timing different from that of the other first lines. This makes it possible to configure a physical reservoir unit having both the nonlinearity of a delay network and a continuous medium type, thereby improving the efficiency of learning.

[0021] In the quantum computing method of the above aspect, the individual supply of the input signal may include supplying the input signal to each first line with a signal waveform different from that of the other first lines. This makes it possible to configure a physical reservoir unit having both the nonlinearity of a delay network and a continuous medium type, thereby improving the efficiency of learning.

[0022] In the quantum computing method of the above aspect, individually supplying input signals may include supplying the input signals to at least one first line, and outputting a read signal may include outputting the read signal from a read circuit that is electromagnetically coupled to a superconducting line corresponding to the at least one first line to which the input signal is supplied.

[0023] An input signal is supplied to at least one first line, and a readout signal is output from a readout circuit in which the first line is electromagnetically coupled to a corresponding superconducting line, thereby enabling computation by quantum annealing. Thus, in the quantum computing method, computation by quantum annealing is possible in addition to physical reservoir computing.

[0024] The quantum computing method of the above aspect may further include individually supplying an adjustment signal to each of a plurality of second lines electromagnetically coupled to each of the plurality of superconducting lines, thereby making it possible to more finely adjust the state of the quantum bit in the superconducting line and more finely adjust the nonlinearity of the read signal with respect to the input signal. Effect of the Invention

[0025] According to the present invention, it is possible to provide a quantum circuit, a quantum computing element, a quantum computing system, and a quantum computing method that enable physical reservoir computing with high learning efficiency. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram showing an overview of a quantum computing system according to a first embodiment. [Diagram 2] 3 is a diagram illustrating the relationship between an input signal and a read signal in the quantum computing device according to the first embodiment. FIG. [Diagram 3] FIG. 2 is a diagram illustrating the concept of an input signal and a read signal in the quantum computing device according to the first embodiment. [Figure 4] 4 is a flowchart of a process in the control device according to the first embodiment. [Diagram 5]FIG. 2 is a diagram illustrating an example of the operation of the quantum computing system according to the first embodiment. [Figure 6] FIG. 11 is a diagram illustrating another example of the operation of the quantum computing system according to the first embodiment. [Figure 7] FIG. 11 is a diagram illustrating another example of the operation of the quantum computing system according to the first embodiment. [Figure 8] FIG. 1 is a diagram showing an overview of a quantum computing device according to a second embodiment. [Figure 9] FIG. 13 is a diagram illustrating an overview of a quantum computing system according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to the accompanying drawings, in which like reference numerals denote like or similar structures.

[0028] [First embodiment] A first embodiment will be described. Fig. 1 shows a schematic diagram of a quantum computing system 10 according to the first embodiment. The quantum computing system 10 includes a quantum circuit 100 and a control device 200. The quantum computing system 10 is a system in which the quantum circuit 100 is controlled by the control device 200 to perform quantum computing.

[0029] The quantum circuit 100 includes superconducting lines 101, 102, 103, and 104, variable couplers C13, C23, C14, and C24, and readout circuits R1, R2, R3, and R4. The quantum circuit 100 is used in a state cooled to a temperature below the superconducting transition temperature of the materials forming the superconducting lines 101, 102, 103, and 104, the variable couplers C13, C23, C14, and C24, and the readout circuits R1, R2, R3, and R4. Therefore, the quantum computing system 10 includes a mechanism (not shown) for cooling the quantum circuit 100.

[0030] Each of the superconducting lines 101, 102, 103, and 104 constitutes a quantum bit by its electromagnetic state. Specifically, the quantum state of the quantum bit is represented by the direction of rotation of the current flowing through the superconducting line. In Fig. 1, the superconducting line 101 and the superconducting line 102 are arranged in the horizontal direction, and the superconducting line 103 and the superconducting line 104 are arranged in the vertical direction.

[0031] The superconducting line 101 is provided so as to be electromagnetically coupled to a line L11 (first line) for applying a transverse magnetic field to the superconducting line 101. The line L11 individually receives an input signal from the control device 200. The line L11 has a line portion facing a part of the superconducting line 101, and is electromagnetically coupled to the superconducting line 101 by the line portion. In this embodiment, the points where the parts of the superconducting line and other members are electromagnetically coupled are illustrated by rectangles in the superconducting lines 101, 102, 103, and 104. Note that facing means that a part of the superconducting line and a part of the line L11 overlap in a plan view.

[0032] A line L21 (second line) for applying a self-magnetic field to the superconducting line 101 is provided so as to be electromagnetically coupled to the superconducting line 101. The line L21 has a line portion facing a part of the superconducting line 101, and is electromagnetically coupled to the superconducting line 101 by the line portion.

[0033] The lines L11 and L21 are connected to the control device 200. A magnetic field controlled by the control device 200 is applied to the superconducting line 101 through the lines L11 and L21, whereby the energy state of the superconducting line 101 is controlled.

[0034] The superconducting line 101 is provided with a read circuit R1 for reading out the state of the quantum bit of the superconducting line 101. The read circuit R1 has a superconducting quantum interference device (SQUID). In FIG. 1, a superconducting quantum interferometer R11 is illustrated in a schematic manner. The read circuit R1 is connected to the control device 200 through a line. In the read circuit R1, a magnetic flux is applied to the superconducting quantum interferometer R11 based on a signal from the control device 200. The read circuit R1 outputs a read signal based on the state of the quantum bit of the superconducting line 101 to the control device 200 by the interaction between the applied magnetic flux and the superconducting line 101.

[0035] The superconducting line 102 is provided with lines L12 and L22 and a read circuit R2, similar to the superconducting line 101. The superconducting line 103 is provided with lines L13 and L23 and a read circuit R3, similar to the superconducting line 101. The superconducting line 104 is provided with lines L14 and L24 and a read circuit R4, similar to the superconducting line 101.

[0036] Variable coupler C13 includes ring portions that face superconducting lines 101 and 103 without contacting each other, and causes superconducting lines 101 and 103 to interact with each other through electromagnetic induction. The strength of the interaction can be adjusted accordingly.

[0037] The variable coupler C23, like the variable coupler C13, causes the superconducting line 102 and the superconducting line 103 to interact with each other through electromagnetic induction. The variable coupler C14, like the variable coupler C13, causes the superconducting line 101 and the superconducting line 104 to interact with each other through electromagnetic induction. The variable coupler C24, like the variable coupler C13, causes the superconducting line 102 and the superconducting line 104 to interact with each other through electromagnetic induction. The variable coupler may be provided to cause any pair of the superconducting lines 101, 102, 103, and 104 to interact with each other. The number of variable couplers does not need to be four as in FIG. 1, and the number of variable couplers can be adjusted as appropriate.

[0038] In the quantum circuit 100, the number of superconducting lines is four, but the number is not limited to four, and a configuration using more lines may be used. Accordingly, the numbers of the first lines, second lines, and readout circuits also increase.

[0039] The control device 200 is a computer that causes the quantum circuit 100 to execute quantum computation. The control device 200 includes a ROM, a RAM, a CPU, etc. The control device 200 executes a process of controlling the quantum computation in the quantum circuit 100 by the CPU executing a program stored in the control device 200.

[0040] The relationship between the input signal and the read signal in the quantum computing system 10 will be described with reference to FIGS.

[0041] FIG. 2 is a graph showing an example of a read signal output from a read circuit when an input signal is input to a superconducting line in a quantum circuit 100. The horizontal axis represents the magnitude of the input signal, which is expressed as a current value. The input signal as a current is converted to a magnetic flux through the line and input to the superconducting line. The state of the quantum bit of each superconducting line changes according to the interaction between the superconducting lines 101, 102, 103, and 104 in the quantum circuit 100. The read signal on the vertical axis is obtained as a current value according to the state of the quantum bit of the corresponding superconducting line.

[0042] 2, the read signal does not necessarily increase with an increase in the input signal, that is, in the quantum circuit 100, the read signal does not change linearly with respect to the input signal, but changes nonlinearly.

[0043] FIG. 3 shows a diagram for explaining the concept of input and readout of a signal. As shown in FIG. 3, a magnetic flux as an input signal is supplied to the superconducting line through the first line over a certain period of time. The magnetic flux here is controlled by a current value, as described above. The magnetic flux as an input signal is continuously supplied to the superconducting line, and the state of the quantum bit in the superconducting line changes. At this time, the readout signal output by the readout circuit is output as a continuous signal that changes nonlinearly with time according to the interaction between the superconducting lines in the quantum circuit 100. Note that, although the input signal is exemplified in FIG. 3 as a signal whose magnetic flux intensity is saturated, it may be a nonlinear curve. Even in this case, the read signal is output as a continuous signal that changes nonlinearly with time in response to the interaction between the superconducting lines in the quantum circuit 100 .

[0044] In this way, a nonlinear read signal corresponding to an input signal is output in the quantum circuit 100. Therefore, the quantum circuit 100 can function as a physical reservoir in physical reservoir computing.

[0045] FIG. 4 is a flowchart showing an example of a process in which the control device 200 controls the calculation in the quantum circuit 100.

[0046] In step S401, the control device 200 selects a first line to supply an input signal. At this time, the control device 200 acquires information specifying a calculation mode in the quantum circuit 100 from an external device, for example, and selects the first line based on the information.

[0047] In step S402, the control device 200 selects a readout circuit from which to obtain a readout signal. As in step S401, the control device 200 obtains information specifying a calculation mode in the quantum circuit 100 from an external device, and selects a readout circuit based on the information.

[0048] In step S403, the control device 200 supplies an input signal to the selected first line. Specifically, the control device 200 supplies a current to the first line for controlling a magnetic flux applied to the superconducting line corresponding to the selected first line.

[0049] In step S404, the control device 200 supplies an adjustment signal to a second line corresponding to the first line. Specifically, the control device 200 supplies a current to the second line for controlling the magnetic flux supplied to the superconducting line through the second line corresponding to the selected first line. Note that the process in step S404 may be omitted, and the control device 200 may supply a current only to the first line.

[0050] In step S405, the control device 200 acquires a read signal from the selected read circuit. Specifically, the control device 200 applies a magnetic flux to a superconducting quantum interferometer corresponding to the selected read circuit, and acquires the read signal as a current signal from the superconducting quantum interferometer.

[0051] In the above steps, a case has been described in which the first line is selected, an input signal is supplied to the first line, and finally an adjustment signal is supplied to the second line. The control device 200 may select the second line instead of the first line in step S401. In this case, the control device 200 may supply the adjustment signal to the second line instead of the first line in step S403. Finally, the control device 200 may supply the input signal to the first line corresponding to the second line instead of the second line in step S404. The control device 200 may supply a current only to the second line. Even when the second line is selected, the readout in step S405 is possible.

[0052] Specific examples of the selection of the first line and the selection of the readout circuit in the quantum computing system 10 will be described with reference to Fig. 5 to Fig. 7. A first specific example is shown in Fig. 5. Fig. 5 shows a situation in which the line L13 corresponding to the superconducting line 103 is selected as the supply destination of the input signal, and the readout circuit R3 corresponding to the superconducting line 103 and the readout circuit R4 corresponding to the superconducting line 104 are selected as the acquisition source of the readout signal.

[0053] At this time, the read signal from the read circuit R3 and the read signal from the read circuit R4 become different signals due to the interactions in the superconducting lines 101, 102, 103, and 104.

[0054] In this way, in the quantum computing system 10, the input signals can be supplied to the first lines whose number is less than the number of readout circuits that output the readout signals. This allows the quantum circuit 100 to function as a delay network type physical reservoir unit that can output readout signals having multiple nonlinearities in response to one input signal.

[0055] A second specific example is illustrated in Fig. 6. Fig. 6 illustrates a situation in which lines L11, L12, L13, and L14 corresponding to the superconducting lines 101, 102, 103, and 104 are selected as destinations of input signals, and a read circuit R2 corresponding to the superconducting line 102 is selected as a source of a read signal.

[0056] At this time, the read signal from the read circuit R2 becomes a signal according to the interactions in the superconducting lines 101, 102, 103, and 104. In this manner, in the quantum computing system 10, input signals can be supplied to each of the first lines, the number of which is greater than the number of read circuits that output read signals. This allows the quantum circuit 100 to function as a continuous medium type physical reservoir unit capable of outputting read signals having at least one or more nonlinearities in response to a plurality of input signals.

[0057] Also, for example, the control device 200 can supply signals having the same signal waveform to the lines L11, L12, L13, and L14 at different timings. In this case, the read signal from the read circuit R2 contains nonlinearity based on the input signal with a time delay in addition to nonlinearity due to the interactions in the superconducting lines 101, 102, 103, and 104, and thus becomes a read signal with higher nonlinearity. This makes it possible to increase the nonlinearity of the read signal.

[0058] Also, for example, the control device 200 can supply input signals having signal waveforms different from those of the other lines to each of the lines L11, L12, L13, and L14. In this case, the read signal from the read circuit R2 includes nonlinearity due to the difference in the magnitude of the input signals in addition to nonlinearity due to the interactions in the superconducting lines 101, 102, 103, and 104, and thus becomes a read signal having higher nonlinearity. This can increase the nonlinearity of the read signal.

[0059] A third specific example is illustrated in Fig. 7. Fig. 6 illustrates a situation in which lines L11, L12, L13, and L14 corresponding to the superconducting lines 101, 102, 103, and 104 are selected as destinations of input signals, and readout circuits R1, R2, R3, and R4 corresponding to the superconducting lines 101, 102, 103, and 104 are selected as sources of readout signals.

[0060] At this time, in the quantum circuit 100, the states of the quantum bits of the superconducting lines 101, 102, 103, and 104 are set individually. The states of the individual quantum bits are set based on input signals supplied to the lines L11, L12, L13, and L14 and adjustment signals supplied to the lines L21, L22, L23, and L24. Also, readout signals resulting from the interaction are output from readout circuits corresponding to the superconducting lines 101, 102, 103, and 104, respectively. Therefore, the quantum circuit 100 can perform calculations by quantum annealing. In this manner, the quantum circuit 100 can be a physical reservoir device that enables physical reservoir computing, and a quantum annealing device that enables calculations by quantum annealing.

[0061] Although the quantum circuit 100 is illustrated as having two superconducting lines 101 and 102 arranged in the horizontal direction and two superconducting lines 103 and 104 arranged in the vertical direction, the number and arrangement of the superconducting lines are not limited to those illustrated. For example, the quantum circuit may have four superconducting lines arranged in the horizontal direction and four superconducting lines arranged in the vertical direction. In this case, the state of the quantum bit of some of the eight superconducting lines may be set, and the state of the quantum bit after annealing may be read out. The superconducting lines to be used are selected according to the Hamiltonian that expresses the problem to be solved by the quantum circuit. When the quantum circuit of this embodiment is used for quantum annealing, some or all of the superconducting lines may be used in the quantum circuit.

[0062] The quantum circuit may have a plurality of unit cells each having two superconducting lines arranged in a horizontal direction and two superconducting lines arranged in a vertical direction, and the unit cells may be arranged so as to be electromagnetically connected to each other. The unit cell may have four superconducting lines arranged in a horizontal direction and four superconducting lines arranged in a vertical direction. When a quantum circuit is configured by connecting a plurality of unit cells, the first line, the second line, and the readout circuit included in some unit cells may not be used depending on the Hamiltonian.

[0063] [Second embodiment] A second embodiment will now be described. Fig. 8 shows a schematic diagram of a quantum computing device 800 according to the second embodiment. The quantum computing device 800 is provided with a quantum circuit 100 and a quantum circuit 801. The quantum circuit 801 may be a quantum circuit different from the quantum circuit 100 in the number of superconducting lines or the way in which variable couplers are coupled. In this way, by providing a plurality of quantum circuits in one quantum computing device 800, a single chip can perform a plurality of quantum calculations.

[0064] [Third embodiment] A third embodiment will now be described. Fig. 9 shows a schematic diagram of a quantum computing system 10A according to the third embodiment. The quantum computing system 10A has control devices 200, 902, a computation management device 901, a signal generating device 903, dilution refrigerators 2001, 9021, and quantum computing elements 2002, 9022. Here, the quantum circuit 100 is formed in the quantum computing element 2002 arranged in the dilution refrigerator 2001.

[0065] The control devices 200 and 902, the calculation management device 901, and the signal generating device 903 are communicatively connected to each other via a network N.

[0066] The computation management device 901 is a computer that manages computation in the quantum computing system 10A by executing a process for selecting a quantum computing element that performs a quantum computation.

[0067] The control device 902 is a computer that controls quantum computing using a quantum computing element 9022 arranged in a dilution refrigerator 9021. The quantum computing element 9022 performs a different type of quantum computing from that of the quantum computing element 2002. For example, the quantum computing element 2002 has the quantum circuit 100 and therefore performs quantum computing by an annealing method, whereas the quantum computing element 9022 can perform quantum computing by a gate method or a quantum dot method. In the quantum computing system 10A, a dilution refrigerator 9021 is used, but a refrigerator of a different type from the dilution refrigerator may be used.

[0068] The signal generating device 903 is, for example, a computer that generates a signal based on a signal from an external sensor (not shown). The signal generated by the signal generating device 903 is transmitted to the calculation management device 901.

[0069] The computation management device 901 selects a quantum computing element suitable for processing the signal based on the signal from the signal generation device 903. Depending on the selection result, the computation management device 901 transmits an element selection signal indicating the quantum computing element that performs the quantum computation to the control device 200 or the control device 902.

[0070] The control device 200 or the control device 902 that receives the element selection signal controls the quantum computing by the corresponding quantum computing element 2002 or quantum computing element 9022 .

[0071] In the quantum computing system 10A, the signal generating device 903 can transmit a signal to the computing management device 901 based on a signal from a device such as a sensor on the edge side. This enables physical reservoir computing while making it possible to utilize the computation results from multiple quantum computing elements. Also, physical reservoir computing using signals from devices such as sensors on the edge side is possible.

[0072] In the quantum computing system 10A, the control device 902 has been described as controlling quantum operations performed by the quantum computing element 9022, but the control target of the control device 902 is not limited to the quantum computing element 9022. For example, the control device 902 may be used to control a quantum computer that uses light, a pseudo-quantum computer realized using an FPGA (Field Programmable Gate Array) or a CMOS circuit, a computer that performs conventional classical operations, a supercomputer, or the like.

[0073] The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangements, materials, conditions, shapes, sizes, etc., are not limited to those shown as examples and can be changed as appropriate. In addition, configurations shown in different embodiments can be partially substituted or combined with each other. [Explanation of symbols]

[0074] 10, 10A... quantum computing system, 100, 801... quantum circuit, 101, 102, 103, 104... superconducting line, 200... control device, 800... quantum computing element, 901... computation management device, 902... control device, 903... signal generating device, L11, L12, L13, L14... line, R1, R2, R3, R4... readout circuit

Claims

1. A method for producing a quantum bit by using a plurality of first lines, the first lines being electromagnetically coupled to each of the plurality of superconducting lines that constitute a quantum bit based on an electromagnetic state, the first lines being individually supplied with an input signal at a timing different from that of the other first lines; a readout signal is output from each of a plurality of readout circuits electromagnetically coupled to each of the plurality of superconducting lines based on a state of the quantum bit of a corresponding superconducting line; A quantum computing method comprising:

2. An input signal having an amplitude different from that of an input signal input to other first lines is individually supplied to each of a plurality of first lines that are electromagnetically coupled to each of a plurality of superconducting lines that configure a quantum bit based on an electromagnetic state; a readout signal is output from each of a plurality of readout circuits electromagnetically coupled to each of the plurality of superconducting lines based on a state of the quantum bit of a corresponding superconducting line; A quantum computing method comprising:

3. A quantum computing method according to claim 1 or 2, The quantum computing method, wherein outputting the readout signal includes outputting the readout signal which is a continuous signal.

4. A quantum computing method according to claim 1 or 2, The quantum computing method, wherein the input signal is supplied individually includes supplying the input signal to each of first lines whose number is less than the number of readout circuits that output the readout signal.

5. A quantum computing method according to claim 1 or 2, The quantum computing method, wherein the input signal is supplied individually includes supplying the input signal to each of first lines whose number is greater than the number of readout circuits that output the readout signal.

6. A quantum computing method according to claim 1 or 2, The input signals being individually supplied includes the input signal being supplied to at least one of the first lines; The quantum computing method, wherein outputting the read signal includes outputting the read signal from the read circuit that is electromagnetically coupled to the superconducting line corresponding to at least one of the first lines to which the input signal is supplied.

7. A quantum computing method according to claim 1 or 2, The quantum computing method further comprising: providing an adjustment signal individually to each of a plurality of second lines electromagnetically coupled to a respective one of the plurality of superconducting lines.

8. A quantum bit is formed by electromagnetic states, and multiple superconducting lines that interact with each other. a plurality of first lines electromagnetically coupled to the plurality of superconducting lines, each of the first lines being configured to be able to individually receive an input signal at a timing different from that of the other first lines; a plurality of second lines electromagnetically coupled to the plurality of superconducting lines, respectively; a plurality of readout circuits electromagnetically coupled to the plurality of superconducting lines, each readout circuit being configured to be capable of outputting a readout signal based on a state of the quantum bit of a corresponding superconducting line; A quantum circuit comprising:

9. A quantum bit is formed by an electromagnetic state, and a plurality of superconducting lines that interact with each other; a plurality of first lines electromagnetically coupled to the plurality of superconducting lines, each of the first lines being configured to be able to individually receive an input signal having an amplitude different from an input signal input to the other first lines; a plurality of second lines electromagnetically coupled to the plurality of superconducting lines, respectively; a plurality of readout circuits electromagnetically coupled to the plurality of superconducting lines, each readout circuit being configured to be capable of outputting a readout signal based on a state of the quantum bit of a corresponding superconducting line; A quantum circuit comprising:

10. A quantum computing element having the quantum circuit described in claim 8 or 9.

11. The quantum computing device according to claim 10, A quantum computing device further comprising a quantum circuit different from the quantum circuit.

12. A quantum computing device according to claim 10; a controller configured to provide the input signal to the quantum computing device and to obtain the readout signal from the quantum computing device; A quantum computing system comprising:

13. The quantum computing system of claim 12, a signal generating device communicatively connected to the control device and generating a first signal; The control device is configured to provide the input signal to the quantum computing element based on the first signal.

14. The quantum computing system of claim 12, the quantum computing device is a first quantum computing device, and the control device is a first control device; A second quantum computing device; and a second controller configured to control computation at the second quantum computing device; The quantum computing system further includes a computation management device communicatively connected to the first control device and the second control device and configured to supply an element selection signal indicating a quantum computing element that performs quantum computation to the first control device or the second control device.

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