Computing device, setting device, setting method, and recording medium

Abstract

A computing device according to the present invention includes a plurality of quantum bit devices, a multi-body coupler that is a three-body or more coupler, and one or more two-body couplers. One or more of three or more of the quantum bit devices coupled by the multi-body coupler are each two-body coupled to the other quantum bit devices by the two-body coupler.

Description

Arithmetic device, setting device, setting method, and recording medium

[0001] The present invention relates to a computing device, a setting device, a setting method, and a recording medium.

[0002] One method for searching for a solution to a combinatorial optimization problem is quantum annealing (see, for example, Patent Document 1).

[0003] International Publication No. 2021 / 172593

[0004] When a problem to be solved by quantum annealing is represented by a loosely coupled graph, it is preferable that the scale of the computing device that executes quantum annealing be as small as possible.

[0005] An example of an object of the present invention is to provide a calculation device, a setting device, a setting method, and a recording medium that can solve the above-mentioned problems.

[0006] According to a first aspect of the present invention, an arithmetic unit includes a plurality of quantum bit devices, a multi-body coupler that is a coupler with three-body or more coupling, and one or more two-body couplers, and one or more of the three or more quantum bit devices coupled by the multi-body coupler are each two-body coupled to another of the quantum bit devices by the two-body coupler.

[0007] According to a second aspect of the present invention, a setting apparatus includes a plurality of quantum bit devices, a multi-body coupler that is a coupler with three-body or more coupling, and one or more two-body couplers, and includes setting means for setting values ​​of parameters of an arithmetic apparatus in which one or more of the three or more quantum bit devices coupled by the multi-body coupler are each two-body coupled to another of the quantum bit devices by the two-body coupler.

[0008] According to a third aspect of the present invention, a setting method includes a computer setting values ​​of parameters of an arithmetic apparatus comprising a plurality of quantum bit devices, a multi-body coupler that is a three-body or greater coupled coupler, and one or more two-body couplers, wherein one or more of the three or more quantum bit devices coupled by the multi-body couplers are each two-body coupled to another of the quantum bit devices by the two-body couplers.

[0009] According to a fourth aspect of the present invention, a recording medium is a recording medium having recorded thereon a program that causes a computer to set values ​​of parameters of an arithmetic unit that includes a plurality of quantum bit devices, a multi-body coupler that is a three-body or more coupled coupler, and one or more two-body couplers, wherein one or more of the three or more quantum bit devices coupled by the multi-body couplers are each two-body coupled to another of the quantum bit devices by the two-body couplers.

[0010] According to the present invention, when a problem to be executed in quantum annealing is represented by a loosely coupled graph, it is expected that the scale of the computing device that executes quantum annealing can be made relatively small.

[0011] 7 is a diagram illustrating an example of a configuration of a computing system according to at least one embodiment; FIG. 8 is a diagram illustrating an example of a configuration of a computing device according to at least one embodiment; FIG. 9 is a diagram illustrating another example of a configuration of a computing device according to at least one embodiment; FIG. 10 is a diagram illustrating an example of a configuration of a control device according to at least one embodiment; FIG. 11 is a diagram illustrating an example of a complete graph; FIG. 12 is a diagram illustrating an example of a physical model obtained by the LHZ method; FIG. 13 is a diagram illustrating an example of a logical model shown in a loosely coupled graph; FIG. 14 is a diagram illustrating an example of an allocation of physical bits to a logical model shown in a loosely coupled graph; FIG. 15 is a diagram illustrating an example of a physical model corresponding to the logical model shown in the loosely coupled graph in the example of FIG. 7; FIG. 16 is a diagram illustrating an example of a logical model including three-body or more couplings; FIG. 17 is a diagram illustrating an example of an allocation of physical bits to a logical model including three-body or more couplings; FIG. 18 is a diagram illustrating an example of a physical model corresponding to a logical model including three-body or more couplings; FIG. 19 is a diagram illustrating an example of a model to be implemented in a computing device according to at least one embodiment; FIG. 11 is a diagram illustrating an example of implementation of a physical model in a computing device according to at least one embodiment; FIG. 12 is a diagram illustrating an example of implementation of the physical model in the example of FIG. 9 in a computing device according to at least one embodiment; FIG. 13 is another example of a logical model to be implemented in a computing device according to at least one embodiment; FIG. 14 is a diagram illustrating yet another example of implementation of a physical model in a computing device according to at least one embodiment; FIG. 1 is a diagram illustrating an example of a processing procedure performed by a computing device according to at least one embodiment; FIG. 2 is a diagram illustrating yet another example of the configuration of a computing device according to at least one embodiment; FIG. 3 is a diagram illustrating an example of a case where a physical model is implemented in a computing device according to at least one embodiment; FIG. 4 is a diagram illustrating another example of a case where a physical model is implemented in a computing device according to at least one embodiment; FIG. 5 is a diagram illustrating an example of a model implemented in a computing device according to at least one embodiment; FIG. 6 is a diagram illustrating another example of the configuration of a computing device according to at least one embodiment; FIG. 7 is a diagram illustrating an example of the configuration of a setting device according to at least one embodiment; FIG. 8 is a diagram illustrating an example of a processing procedure in a setting method according to at least one embodiment; FIG. 9 is a diagram illustrating an example of the configuration of a computer according to at least one embodiment.

[0012] The following describes embodiments of the present invention, but the following embodiments do not limit the scope of the invention as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0013] First Embodiment Fig. 1 is a diagram showing an example of the configuration of a computing system according to at least one embodiment. In the configuration shown in Fig. 1, the computing system 1 includes a computing device 100 and a control device 200.

[0014] The computing system 1 is a system that executes quantum annealing. Specifically, the computing device 100 executes quantum annealing under the control of the control device 200. Quantum annealing here refers to a solution search that utilizes quantum mechanical properties. The combinatorial optimization problem that is the target of the solution search by the computing system 1 is also referred to as the target problem.

[0015] The computing device 100 receives an implementation of a physical model of a target problem and performs a solution search using the physical model. The physical model here is a model that expresses the problem being solved in a format that can be implemented on hardware that executes quantum annealing. The computing device 100 is an example of a quantum annealing machine or a quantum computer.

[0016] Here, if the target problem is directly modeled, it may be difficult to implement the obtained model in the arithmetic device 100. Therefore, it may be possible to obtain a model that expresses the target problem in a format that can be implemented in the arithmetic device 100 by performing transformations such as variable replacement on the target problem before modeling it.

[0017] A model that expresses a target problem in a format that can be implemented in the computing device 100, obtained by converting and then modeling the target problem, is an example of a physical model. Binary variables used in a physical model are called physical bits. On the other hand, a model that is converted into a physical model, such as a model obtained by directly modeling the problem that is the target of a solution search, is called a logical model. Binary variables used in a logical model are called logical bits. Physical bits and logical bits are collectively referred to as quantum bits.

[0018] The control device 200 controls the arithmetic device 100 to execute quantum annealing. In particular, the control device 200 sets parameter values ​​for the arithmetic device 100 to execute quantum annealing. The control device 200 may be configured using a classical computer (von Neumann computer). Alternatively, the control device 200 may be configured using dedicated hardware, such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0019] 2 is a diagram showing an example of the configuration of the computing device 100. In the configuration shown in FIG. 2, the computing device 100 includes a quantum bit device 110, a four-body coupler 120, and a two-body coupler .

[0020] The quantum bit device 110 is a device that represents the value of a physical bit. Specifically, the quantum bit device 110 has two final states, and by taking one of the two states, it represents the value of the physical bit as a result of one solution search using quantum annealing. The final state here refers to the state at the end of one solution search using quantum annealing.

[0021] There is no particular limitation on the method for realizing the quantum bit device 110. For example, the quantum bit device 110 may be configured using a Josephson parametric oscillator (JPO), but is not limited to this.

[0022] In the following, an example will be described in which the physical bit takes on a value of either +1 or −1. However, the physical bit here may be a binary variable, and the value that the physical bit takes is not limited to a specific value. For example, the physical bit may be defined to take on a value of either 0 or 1.

[0023] The four-body coupler 120 causes interaction between the four quantum bit devices 110. Here, causing the quantum bit devices 110 to interact means causing correlation between the states of the multiple quantum bit devices 110.

[0024] A coupler configured to allow multiple qubit devices 110 to interact with each other is also referred to as the coupler coupling the multiple qubit devices 110. For example, the coupling of the qubit devices 110 may be achieved by electrically connecting the qubit devices 110 to the coupler.

[0025] The coupling of n qubit devices 110 is also referred to as n-body coupling of the qubit devices 110, where n is an integer greater than or equal to 2. For example, the coupling of four qubit devices 110 via a four-body coupler 120 is also referred to as four-body coupling. The interaction of n qubit devices 110 is also referred to as n-body interaction of the qubit devices 110, where n is an integer greater than or equal to 2. For example, the interaction of four qubit devices 110 via a four-body coupler 120 is also referred to as four-body interaction.

[0026] Control of the quantum bit device 110 by the coupler can be considered as control of the physical bit represented by the quantum bit device 110. Hereinafter, the quantum bit device 110 may be expressed as the physical bit represented by the quantum bit device 110. Furthermore, the state of the quantum bit device 110 may be expressed as the value of the physical bit represented by the quantum bit device 110.

[0027] The interaction of the qubit devices 110 is also referred to as the interaction of the physical bits. The interaction of the physical bits can be considered as causing correlation between the values ​​of multiple physical bits. The coupling of the qubit devices 110 is also referred to as the coupling of the physical bits. The coupling of the qubits can be considered as the values ​​of multiple coupled physical bits being able to interact with each other.

[0028] An interaction strength can be set for the four-body combiner 120, and the four-body combiner 120 controls the four physical bits with a control strength corresponding to the set interaction strength so that the parity of the four physical bits becomes even. Control of the parity with the set strength can be considered as control of the parity with a set probability.

[0029] Here, when a physical bit has a value of either +1 or −1, the parity of the physical bit is calculated by multiplying the physical bit value. In this case, even parity is defined as a parity value of +1, and odd parity is defined as a parity value of −1.

[0030] The interaction strength can also be referred to as correlation strength or coupling strength. Setting the interaction strength for the four-body coupler 120 corresponds to an example of setting parameter values ​​for the computing device 100 to perform quantum annealing. A known four-body coupler may be used as the four-body coupler 120. A known technique can be used as a technique for the four-body coupler 120 to four-body couple (cause four-body interaction) the four quantum bit devices 110. For example, the four-body coupler 120 may four-body couple the quantum bit devices 110 using the method described in International Publication No. 2021 / 014885.

[0031] The two-body coupler 130 causes the states of the two quantum bit devices 110 to interact with each other. An interaction strength can be set for the two-body coupler 130, and the two-body coupler 130 constrains the final values ​​of the two physical bits so that the parity of the two physical bits is even, with a constraint strength corresponding to the set interaction strength. Setting the interaction strength for the two-body coupler 130 corresponds to an example of setting parameter values ​​for the computing device 100 to perform quantum annealing. A known two-body coupler may be used as the two-body coupler 130. Known techniques can be used for the two-body coupler 130 to two-body couple (two-body interact) the two quantum bit devices 110 to achieve even parity. For example, two-body coupling may be achieved by connecting oscillators (quantum bit devices 110) together using a capacitor. For example, the two-body coupler 130 may two-body couple the quantum bit devices 110 using a method described in Japanese Patent Application Laid-Open No. 2023-76272.

[0032] When distinguishing between multiple four-body couplers 120, they are also referred to as four-body couplers 120-1, 120-2, etc. When distinguishing between multiple quantum bit devices 110, the four quantum bit devices 110 coupled by a four-body coupler 120-i are also referred to as quantum bit devices 110-ia, 110-ib, 110-ic, and 110-id, where i is an integer greater than or equal to 1.

[0033] For example, the four quantum bit devices 110 coupled by the four-body coupler 120-1 are also referred to as quantum bit devices 110-1a, 110-1b, 110-1c, and 110-1d.

[0034] Furthermore, the quantum bit devices 110 that are not directly coupled by the four-body coupler 120 are also denoted as quantum bit devices 110-01, 110-02, . . .

[0035] When distinguishing between multiple two-body couplers 130, a two-body coupler 130 that couples a quantum bit device 110 coupled by a four-body coupler 120-i and a quantum bit device 110 coupled by a four-body coupler 120-j is also referred to as a two-body coupler 130-ij. Here, i is an integer greater than or equal to 1, and j is an integer greater than or equal to i. For example, a two-body coupler 130 that couples quantum bit device 110-1b and quantum bit device 110-2a is also referred to as a two-body coupler 130-12.

[0036] Furthermore, a two-body coupler 130 that couples quantum bit devices 110 that are coupled by a four-body coupler 120 with quantum bit devices 110 that are not directly coupled by a four-body coupler 120 may be represented by a symbol following "-" to distinguish the quantum bit devices 110 that are coupled by the four-body coupler 120. For example, a two-body coupler 130 that couples quantum bit devices 110-1d and 110-01 may also be represented as two-body coupler 130-1d.

[0037] 2, at the outermost portion of the computing device 100, one quantum bit device 110 in each of two four-body couplings is two-body coupled by a two-body coupler 130. The outermost portion of the computing device 100 here refers to the portion corresponding to the sides of the rectangle when the shape of the computing device 100 is considered to be a rectangle. For example, quantum bit device 110-1b and quantum bit device 110-2a are two-body coupled by a two-body coupler 130-12.

[0038] Furthermore, inside the outermost portion of the computing apparatus 100, one quantum bit device 110 in each of the four four-body couplings is two-body coupled to a quantum bit device 110 common to these four quantum bit devices 110 by a two-body coupler 130. For example, quantum bit device 110-1d and quantum bit device 110-01 are two-body coupled by a two-body coupler 130-1d. Quantum bit device 110-2c and quantum bit device 110-01 are two-body coupled by a two-body coupler 130-2c. Quantum bit device 110-4b and quantum bit device 110-01 are two-body coupled by a two-body coupler 130-4b. Quantum bit device 110-5a and quantum bit device 110-01 are two-body coupled by a two-body coupler 130-5a.

[0039] Furthermore, the quantum bit devices 110 at positions corresponding to the four corners of the computing apparatus 100 are not coupled to other quantum bit devices 110 except for the four-body coupling by the four-body coupler 120. For example, quantum bit device 110-1a is not coupled to other quantum bit devices 110 except for the four-body coupling by the four-body coupler 120-1.

[0040] In the example of Figure 2, the qubit devices 110 that are not directly coupled by the four-body couplers 120 are examples of common qubit devices. The common qubit device here is a qubit device common to the qubit devices, where one qubit device among the qubit devices coupled by each multi-body coupler is two-body coupled by a two-body coupler. The multi-body coupling here refers to the coupling of three or more qubit devices. The multi-body coupler here refers to a coupler that couples three or more qubit devices.

[0041] For example, four-body couplers 120-1, 120-2, 120-4, and 120-5 are examples of many-body couplers. Quantum bit device 110-1d corresponds to one of the quantum bit devices 110 coupled by four-body coupler 120-1. Quantum bit device 110-2c corresponds to one of the quantum bit devices 110 coupled by four-body coupler 120-2. Quantum bit device 110-4b corresponds to one of the quantum bit devices 110 coupled by four-body coupler 120-4. Quantum bit device 110-5a corresponds to one of the quantum bit devices 110 coupled by four-body coupler 120-1.

[0042] Quantum bit device 110-01 is coupled to quantum bit device 110-1d by a two-body coupler 130-1d. Quantum bit device 110-01 is coupled to quantum bit device 110-2c by a two-body coupler 130-2c. Quantum bit device 110-01 is coupled to quantum bit device 110-4b by a two-body coupler 130-4b. Quantum bit device 110-01 is coupled to quantum bit device 110-5a by a two-body coupler 130-5a. Quantum bit device 110-01 corresponds to the quantum bit device 110 common to quantum bit devices 110-1d, 110-2c, 110-4b, and 110-5a.

[0043] Here, by setting the interaction strength of the dyadic bond to 0, it is possible to prevent the two physical bits from interacting with each other. Setting the interaction strength to 0 is also referred to as severing the interaction. In the computing device 100, by coupling a four-body coupled physical bit with another physical bit by a two-body coupling as in the example of FIG. 2, it is possible to sever the two-body interaction and prevent the value of the physical bit that is four-body coupled from affecting the value of the other physical bit.

[0044] If the two-body interaction of one of the four-body coupled physical bits is cut off and the value of that physical bit is fixed to +1, the four-body coupling can function as an even-parity three-body coupling without affecting the other four-body couplings. The value of the physical bit can be fixed by controlling the state of the quantum bit device 110 that represents that physical bit.

[0045] For example, consider a case where the two-body interaction by two-body coupler 130-1d is cut off and the value of the physical bit indicated by quantum bit device 110-1d is fixed to +1. In this case, four-body coupler 120-1 can function as a three-body coupler of even parity without affecting the four-body couplings by four-body couplers 120-2, 120-4, and 120-5.

[0046] Furthermore, the four-body coupling can also function as a two-body coupling of even parity. In this case, the two-body interaction is cut for two of the four-body coupled physical bits, and the values ​​of these two physical bits are fixed to +1.

[0047] Alternatively, the four-body coupling can be made to function as a three-body coupling with odd parity. In this case, the two-body coupling for one of the four-body coupled physical bits is cut off, and the value of that physical bit is fixed to -1. Furthermore, the four-body coupling can be made to function as a two-body coupling with odd parity. In this case, the two-body interaction for one of the four-body coupled physical bits is cut off, and the value of one physical bit is fixed to +1, and the value of the other physical bit is fixed to -1.

[0048] In this way, the arithmetic device 100 can handle any of four-body, three-body, and two-body combinations, and in this respect, the arithmetic device 100 can be applied to a variety of physical models.

[0049] The multi-body coupler included in the computing device 100 is not limited to a four-body coupler, and may be a three-body or more coupler. For example, if the computing device 100 includes a three-body coupler, the three-body coupler can perform either a three-body coupler or a two-body coupler. Furthermore, if the computing device 100 includes a five-body coupler, the five-body coupler can perform either a five-body coupler, a four-body coupler, a three-body coupler, or a two-body coupler. Furthermore, the computing device 100 may include multiple types of multi-body couplers. For example, the computing device 100 may include a four-body coupler and a five-body coupler.

[0050] Although Figure 2 shows an example of a configuration in which the arithmetic device 100 includes nine four-body couplers 120, the number of multi-body couplers included in the arithmetic device 100 may be two or more, and is not limited to a specific number.

[0051] Fig. 3 is a diagram showing another example of the configuration of the computing device 100. In the configuration shown in Fig. 3, the computing device 100 includes a quantum bit device 110, a four-body coupler 120, and a two-body coupler 130. Furthermore, a combination of one four-body coupler 120 and four quantum bit devices 110 four-body coupled by that four-body coupler 120 is also referred to as a four-body coupled block 140.

[0052] 3 shows an example of a configuration in which four-body connection blocks 140 are arranged vertically and horizontally. The number of rows of the four-body connection blocks 140 is m, and the number of columns is n. Here, m is an integer m≧1, and n is an integer n≧1. The configuration of the arithmetic device 100 shown in FIG. 2 corresponds to an example in which m=3 and n=3.

[0053] As described above, the number of multi-body couplers included in the arithmetic device 100 may be two or more. Therefore, the number of 4-body coupling blocks 140 included in the arithmetic device 100 may be two or more. For example, m≧2 and n≧1 may be satisfied. When distinguishing between multiple 4-body coupling blocks 140, the 4-body coupling block 140 in the i-th row and j-th column may also be referred to as 4-body coupling block 140-i-j. Here, i is an integer satisfying 1≦i≦m, and j is an integer satisfying 1≦j≦n.

[0054] 2 is used when distinguishing between multiple quantum bit devices 110, when distinguishing between multiple four-body couplers 120, and when distinguishing between multiple two-body couplers 130. For example, the four-body coupler 120 in the four-body coupled block 140-i-j is also denoted as four-body coupler 120-(n(i-1)+j).

[0055] The coupling of physical bits in the example of Fig. 3 is similar to that in the example of Fig. 2. Specifically, in the example of Fig. 3, at the outermost part of the computing device 100, one physical bit of each of two four-body couplings is two-body coupled by a two-body coupler 130. For example, one quantum bit device 110 in four-body coupling block 140-1-1 and one quantum bit device 110 in four-body coupling block 140-1-2 are two-body coupled by the two-body coupler 130.

[0056] Furthermore, inside the outermost portion of the computing device 100, one physical bit of each of the four four-body couplings is two-body coupled to a physical bit common to these four physical bits by a two-body coupler 130. For example, one quantum bit device 110 in each of the four-body coupling blocks 140-1-1, 140-1-2, 140-2-1, and 140-2-2 is two-body coupled to quantum bit device 110-01 common to these four quantum bit devices 110 by a two-body coupler 130.

[0057] Furthermore, the quantum bit devices 110 at positions corresponding to the four corners of the computing apparatus 100 are not coupled to other quantum bit devices 110 except through the four-body coupler 120. For example, quantum bit device 110-1a is not coupled to other quantum bit devices 110 except through the four-body coupling provided by the four-body coupler 120.

[0058] As explained for the example of Fig. 2, the arithmetic device 100 can handle any of four-body bonds, three-body bonds, and two-body bonds in the example of Fig. 3. In this respect, the arithmetic device 100 can be applied to various physical models.

[0059] The configuration of the computing device 100 may be the same as that of Fig. 3 except that one or more four-body coupling blocks 140 are removed. For example, the configuration of the computing device 100 may be the same as that of Fig. 3 except that four-body coupling block 140-1-1 and two-body coupler 130 that couples quantum bit device 110 in four-body coupling block 140-1-1 with another quantum bit device 110 are removed.

[0060] Alternatively, by cutting all dyadic interactions by dyadic couplers 130 that couple quantum bit devices 110 in one or more four-body coupling blocks 140 with other quantum bit devices 110, it is possible to realize a configuration equivalent to a configuration excluding the four-body coupling block 140. For example, by cutting all dyadic interactions between quantum bit devices 110 in four-body coupling block 140-1-1 and other quantum bit devices 110, it is possible to realize a configuration equivalent to a configuration excluding four-body coupling block 140-1-1.

[0061] As described above, the multi-body coupler included in the arithmetic device 100 is not limited to a four-body coupler, and may be a three-body or more coupler. Furthermore, the arithmetic device 100 may be provided with multiple types of multi-body couplers.

[0062] Fig. 4 is a diagram showing an example of the configuration of the control device 200. In the configuration shown in Fig. 4, the control device 200 includes a communication unit 210, a display unit 220, an operation input unit 230, a storage unit 280, and a processing unit 290. The processing unit 290 includes a setting information acquisition unit 291, a setting unit 292, an arithmetic control unit 293, and a solution calculation unit 294.

[0063] The communication unit 210 communicates with other devices. For example, the communication unit 210 may be configured to transmit a control signal to the arithmetic device 100. The communication unit 210 may also be configured to receive a signal indicating an observation result of the state of the quantum bit device 110 from the arithmetic device 100. The communication unit 210 may also be configured to receive a physical model of the target problem from a device that generates the physical model.

[0064] The display unit 220 has a display screen such as a liquid crystal panel or an LED (Light Emitting Diode) panel, and acquires various images. For example, the display unit 220 may display a physical model of the target problem. The display unit 220 may also display the results of quantum annealing.

[0065] The operation input unit 230 includes input devices such as a keyboard and a mouse, and accepts user operations. For example, the operation input unit 230 may accept a user operation to input a setting value related to the execution of quantum annealing, such as the number of iterations of the solution search by quantum annealing. Furthermore, instead of the communication unit 210 receiving a physical model of the target problem, the operation input unit 230 may accept a user operation to generate a physical problem for the target problem.

[0066] The storage unit 280 stores various data. For example, the storage unit 280 may store a physical model of the target problem. The storage unit 280 is configured using a storage device provided in the control device 200. The processing unit 290 controls each unit of the control device 200 to perform various processes. The functions of the processing unit 290 are performed, for example, by a CPU (Central Processing Unit) provided in the control device 200 reading and executing a program from the storage unit 280.

[0067] The setting information acquisition unit 291 acquires information for implementing a physical model of the target problem in the arithmetic device 100. For example, the setting information acquisition unit 291 may extract data indicating the physical model of the target problem from data received by the communication unit 210.

[0068] The setting unit 292 implements a physical model of the target problem in the arithmetic device 100 based on the information acquired by the setting information acquisition unit 291. For example, the setting unit 292 determines the values ​​of each parameter to be set in the arithmetic device 100, such as the bond strength of each four-body bond, the bond strength of each two-body bond, the bias value for each physical bit, and the control parameter value for the physical bit to be set to a fixed value, based on the physical model of the target problem acquired by the setting information acquisition unit 291. Then, the setting unit 292 transmits the determined parameter values ​​to the arithmetic device 100 via the communication unit 210. The setting unit 292 corresponds to an example of setting means. The control device 200 corresponds to an example of a setting device in that it includes the setting unit 292.

[0069] The calculation control unit 293 controls the calculation device 100 to perform quantum annealing. For example, the calculation control unit 293 calculates the value of a time-varying parameter according to time, and transmits the calculated parameter value to the calculation device 100 via the communication unit 210. For example, when a Josephson parametric oscillator is used as the quantum bit device 110, the detuning parameter and the pump parameter are examples of the time-varying parameters.

[0070] Furthermore, the operation control unit 293 acquires data indicating the states of the quantum bit devices 110 as a result of executing quantum annealing. For example, when a predetermined time has elapsed since the start of one solution search by quantum annealing, the communication unit 210 receives a signal indicating the observation result of the state of each quantum bit device 110 from the operation apparatus 100. The operation control unit 293 extracts data indicating the state of each quantum bit device 110 from the data received by the communication unit 210.

[0071] The operation control unit 293 causes the operation device 100 to repeatedly execute a solution search using quantum annealing. For example, in one solution search using quantum annealing, the setting unit 292 sets initial values ​​for the parameters of the operation device 100. Then, the operation control unit 293 changes the values ​​of the time-varying parameters according to time. When a predetermined time has elapsed since the start of one solution search using quantum annealing, the operation control unit 293 acquires data indicating the state of each quantum bit device 110.

[0072] When one solution search using quantum annealing is completed, the calculation control unit 293 determines whether or not a termination condition for the repeated solution search using quantum annealing is satisfied. The termination condition here is not limited to a specific condition. For example, the termination condition here may be, but is not limited to, that the solution search using quantum annealing has been repeated a predetermined number of times.

[0073] If the calculation control unit 293 determines that the termination condition is not met, the setting unit 292 and the calculation control unit 293 continue to control the calculation device 100 to repeatedly execute the solution search in quantum annealing. On the other hand, if the calculation control unit 293 determines that the termination condition is met, the control device 200 ends control for causing the calculation device 100 to execute quantum annealing.

[0074] The solution calculation unit 294 calculates a solution to the target problem based on the results of quantum annealing. For example, the solution calculation unit 294 determines the value of each physical bit based on the state of each quantum bit device 110 obtained for each solution search by quantum annealing. Then, the solution calculation unit 294 calculates a solution to the target problem based on the value of each physical bit.

[0075] The implementation of the physical model of the target problem in the arithmetic device 100, performed by the setting unit 292, will be further described. First, the conversion from a logical model to a physical model will be described. As described above, the physical model is generated so as to have an expression format that can be implemented in hardware (a quantum annealing machine), whereas the logical model does not necessarily have to have an expression format that can be implemented in hardware.

[0076] In the following, the physical model and the logical model may be expressed using graphs, but the method of expressing either the physical model or the logical model is not limited to a specific method. For example, either the physical model or the logical model may be expressed using a mathematical formula such as a Hamiltonian.

[0077] One type of combinatorial optimization problem is one that can be expressed as a complete graph. A complete graph is a graph in which any two nodes are connected by a single edge. The connection of nodes in a complete graph is also called full connectivity.

[0078] 5 is a diagram showing an example of a complete graph. FIG. 5 shows an example of a complete graph in which the number of nodes is five. Any two of the five nodes are connected by one edge. Here, in the graph representation of the logical model, nodes represent logical bits, and edges represent two-body combinations of logical bits.

[0079] The combination of logical bits here means that the values ​​of the multiple logical bits that are combined can interact with each other. The interaction of logical bits means that the values ​​of the multiple logical bits are correlated.

[0080] In the following, an example will be described in which a logical bit takes on either a value of +1 or -1. However, the logical bit here may be a binary variable, and the value that the logical bit takes is not limited to a specific value. For example, if a physical bit takes on either a value of 0 or 1, the logical bit may also be defined to take on either a value of 0 or 1.

[0081] The Hamiltonian of the logical model represented by the complete graph is shown as equation (1).

[0082]

[0083] σ ｉ indicates a logical bit, where i is an index for distinguishing logical bits, and 1≦i≦N Ｌ is an integer. Ｌ indicates the number of logical bits. ｉｊ and h ｊ are constants determined according to the combinatorial optimization problem. ｉｊ is the logical bit σ ｉ and logical bit σ ｊ indicates the bond strength with ｊ is the logical bit σ ｊ Indicates the offset of

[0084] This logic model represents a combinatorial optimization problem that searches for a combination of logic bit values ​​that minimizes the value of the Hamiltonian H. If an attempt were made to implement the logic model expressed as a complete graph directly in a quantum annealing machine, the connections between the quantum bit devices would cross, making implementation difficult.

[0085] Therefore, it is possible to convert the logical model into a physical model and implement it in a quantum annealing machine. One method for converting a logical model expressed as a complete graph into a physical model is the Lechner-Hauke-Zoller (LHZ) method. In the LHZ method, the product of logical bits is represented by a physical bit. For example, the Hamiltonian H in equation (1) is rewritten as equation (2).

[0086]

[0087] σ ０ｊ is a variable whose value is fixed to +1. ０ｊ =h ｊ The Hamiltonian H shown in equation (2) is ０≦ｉ＜ｊ J ｉｊ σ ｉ σ ｊ So, σ ｉ σ ｊ takes on the value of either +1 or −1. Therefore, the Hamiltonian H shown in equation (2) is further rewritten as equation (3).

[0088]

[0089] σ （ｉｊ） is σ ｉ σ ｊ is a variable that indicates the value of . Equation (3) does not include a product of variables. Therefore, according to equation (3), no interaction occurs between the qubit devices. In this respect, the model represented by equation (3) can be more easily implemented in hardware than the model represented by equation (1).

[0090] On the other hand, in formula (3), the degree of freedom of the values ​​that the variables can take is greater than in formula (1). For this reason, the solution obtained by quantum annealing based on formula (3) may not be able to obtain a solution to the original combinatorial optimization problem. For example, σ （１３） = +1, σ （１４） = +1, σ （２３） = +1, σ （２４） Let us consider the case where σ = -1. （１３） = +1, σ （１４） = +1, and σ （２３） From the viewpoint of =+1, σ １ = σ ２ = σ ３ = σ ４ On the other hand, σ （２４） = -1, σ ２ ≠σ ４ is.

[0091] In this way, when calculating the solution to the original combinatorial optimization problem from the solution obtained by quantum annealing, a contradiction may arise, and the solution to the original combinatorial optimization problem may not be obtained. Therefore, instead of the Hamiltonian H shown in equation (3), the Hamiltonian H shown in equation (4) is used.

[0092]

[0093] C [Σσ （ｉｊ） σ （ｉｋ） σ （ｊｋ） +Σσ （ｉｊ） σ （ｉｋ） σ （ｌｊ） σ （ｌｋ） ] is a term for suppressing the occurrence of a contradiction by increasing the value of the Hamiltonian H when the contradiction described above occurs. C is a constant coefficient of C>0.

[0094] Fig. 6 shows an example of a physical model obtained by the LHZ method. Fig. 6 shows an example of a physical model obtained by the LHZ method in the form of a hypergraph. The hypergraph here is a graph that includes edges connecting three or more nodes.

[0095] In the example of Fig. 6, the nodes indicated by white circles (o) represent physical bits. The nodes marked "+1" represent physical bits whose value is fixed to +1, which are provided to control the parity of three physical bits using a four-body combiner. The other nodes are connected to the variable σ （ｉｊ） The edge shown by a combination of a black circle (●) and a line indicates a four-body bond.

[0096] Equation (4) includes a product of variables, and when implemented in hardware, coupling of quantum bit devices occurs. However, as illustrated in Figure 6, this can be a four-body coupling between four adjacent physical bits. Therefore, the physical model using Hamiltonian H shown in equation (4) can be implemented in hardware using a four-body coupler. The physical model using Hamiltonian H shown in equation (4) is also referred to as the LHZ model.

[0097] Here, consider the case where the logical model is represented by a loosely coupled graph. A loosely coupled graph here is a graph that is not a complete graph, that is, a graph in which at least any two nodes are not connected by an edge. When the logical model is represented by a loosely coupled graph, if the LHZ model is used, it is considered that the number of physical bits will be excessive. In particular, the fewer the number of logical bit connections relative to the number of logical bits, the more likely it is that the number of physical bits will be excessive if the LHZ model is used.

[0098] In this case, if the logical model can be converted into a physical model with a smaller number of physical bits than when the LHZ model is used, hardware can be used more effectively. In particular, it is expected that problems with a larger number of logical bits can be solved using the same hardware (hardware with the same number of quantum bit devices) when the logical model is converted into a physical model with a smaller number of physical bits than when the LHZ model is used, compared to when the logical model is converted into an LHZ model. One such method of converting a logical model into a physical model is to construct a physical model using three-body coupling, four-body coupling, or a combination thereof.

[0099] Fig. 7 is a diagram showing an example of a logical model shown in a loosely coupled graph. In the example of Fig. 7, nodes shown as white circles (◯) represent logical bits. In addition, each node is shown with an index for distinguishing the logical bits. Edges shown as lines represent connections between logical bits.

[0100] Fig. 8 is a diagram showing an example of allocation of physical bits to a logical model shown in a loosely coupled graph. Fig. 8 shows an example of allocating physical bits to each bond in the logical model shown in Fig. 7. Allocating physical bits to bonds in the logical model is equivalent to allocating physical bits to the product of logical bits.

[0101] 8 shows the index of a physical bit for each edge of the graph. Also shown in FIG. 8 are connections to be provided in the physical model. Similar to the above-described conversion from a logical model represented by a complete graph to an LHZ model, physical bit connections are provided to prevent inconsistencies from occurring when calculating a solution to the original combinatorial optimization problem from a solution obtained by quantum annealing.

[0102] In the example of Figure 8, there are provided a three-body combination of three physical bits indicated by indexes 12, 16, and 26, a three-body combination of three physical bits indicated by indexes 34, 35, and 45, a four-body combination of four physical bits indicated by indexes 12, 13, 23, and 34, and a four-body combination of four physical bits indicated by indexes 14, 16, 45, and 56.

[0103] Fig. 9 is a diagram showing an example of a physical model corresponding to the logical model shown in the loosely coupled graph in the example of Fig. 7. Fig. 9 shows an example of a physical model corresponding to the logical model shown in Fig. 7, obtained by the physical bit assignment and coupling settings shown in Fig. 8.

[0104] The physical model shown in FIG. 9 is constructed using logical bits, three-body connections, and four-body connections. White circles represent physical bits, and the physical bit index is shown inside the white circles. Triangles represent three-body connections. Squares represent four-body connections. In this way, it is possible to convert a logical model represented by a loosely coupled graph into a physical model using three-body connections, four-body connections, or a combination of these.

[0105] Furthermore, in converting a logical model into a physical model, if the logical model contains three-body or more bonds, the logical model cannot be converted directly into an LHZ model.

[0106] FIG. 10 is a diagram showing an example of a logical model including three-body or more bonds. FIG. 10 shows an example of a logical model in the form of a hypergraph. Nodes shown as white circles represent logical bits, and the index of the logical bit is shown at each node. Edges shown as lines represent two-body bonds. Edges (hyperedges) represented by a combination of a line and a black circle represent three-body bonds.

[0107] Fig. 11 is a diagram showing an example of allocation of physical bits to a logical model including three-body or more bonds. Fig. 11 shows an example of allocating physical bits to each bond in the logical model shown in Fig. 10. In Fig. 11, a physical bit index is shown for each edge (including hyperedges) of the hypergraph.

[0108] Fig. 12 is a diagram showing an example of a physical model corresponding to a logical model including three-body or more bonds. Fig. 12 shows an example of a physical model for the logical model shown in Fig. 10, obtained by the physical bit allocation shown in Fig. 11. In the example of Fig. 12 as well, physical bit bonds are provided to prevent inconsistencies from occurring when calculating a solution to the original combinatorial optimization problem from a solution obtained by quantum annealing.

[0109] The white circles represent physical bits, and the physical bit index is shown inside the white circles. The square shapes represent four-body bonds. In this way, it is possible to convert a logical model that includes three-body or more bonds into a physical model that uses three-body bonds, four-body bonds, or a combination of these.

[0110] The method for obtaining a model using three-body bonding, four-body bonding, or a combination thereof, as exemplified in Figures 9 and 12, is not limited to a specific method. For example, a model using three-body bonding, four-body bonding, or a combination thereof may be obtained using a publicly available model conversion method, but is not limited to this.

[0111] In a physical model using a three-body bond, a four-body bond, or a combination thereof, the positions at which the three-body bond and the four-body bond appear vary depending on the target problem. In contrast, as described above, the arithmetic device 100 can handle any of a four-body bond, a three-body bond, and a two-body bond. Therefore, the arithmetic device 100 can implement models with a variety of positions at which the three-body bond and the four-body bond appear.

[0112] Here, when a model using three-body coupling, four-body coupling, or a combination thereof is implemented in the computing device 100, one quantum bit in the model is assigned to multiple quantum bit devices 110 of the computing device 100. Therefore, hereinafter, a model using field coupling, four-body coupling, or a combination thereof will be treated as a logical model.

[0113] Fig. 13 is a diagram showing an example of a model to be implemented in the computing device 100. Fig. 13 shows an example of a model using four-body coupling. White circles represent quantum bits, and the quantum bit index is shown inside the white circles. Square shapes represent four-body coupling.

[0114] Fig. 14 is a diagram showing an example of implementing a physical model in the computing device 100. Fig. 14 shows an example of implementing a physical model corresponding to the model shown in Fig. 13 in the computing device 100 having the configuration shown in Fig. 2. White circles indicate quantum bit devices 110, and the index of the quantum bit in Fig. 13 corresponding to the quantum bit device 110 is shown inside the white circle. A rectangular shape indicates a four-body coupler 120. A line connecting two white circles indicates a two-body coupler 130.

[0115] Here, Fig. 13 can be regarded as showing an example of a physical model to be implemented in a computing device, and Fig. 14 can be regarded as showing an example of a method of setting up a physical model having the structure shown in Fig. 2 in order to implement the physical model shown in Fig. 13 in a physical model having a more general structure shown in Fig. 2.

[0116] 14, one quantum bit in the example of FIG. 13 is assigned to multiple quantum bit devices 110. For example, the quantum bit with index 1 is assigned to quantum bit devices 110-1b and 110-2a, and the quantum bit with index 2 is assigned to quantum bit devices 110-1d, 110-2c, 110-4b, and 110-5a.

[0117] Such allocation of one quantum bit to multiple quantum bit devices 110 can be achieved by setting the strength of the interaction of the two-body coupler 130 to a strong interaction. The strong interaction here refers to an interaction that brings the states of the multiple quantum bit devices 110 into the same state. The strong interaction may be performed by an interaction with the strongest interaction strength that can be set in the coupler.

[0118] For example, two-body coupler 130-12 causes quantum bit device 110-1b and quantum bit device 110-2a to interact with each other through strong interaction, thereby bringing the quantum bit device 110-1b and the quantum bit device 110-2a into the same state.

[0119] Furthermore, two-body coupler 130-1d causes quantum bit device 110-1d and quantum bit device 110-01 to interact with each other through strong interaction, thereby making the state of quantum bit device 110-1d and the state of quantum bit device 110-01 the same.

[0120] Furthermore, the two-body coupler 130-2c causes the quantum bit device 110-2c and the quantum bit device 110-01 to interact with each other through strong interaction, thereby making the state of the quantum bit device 110-2c and the state of the quantum bit device 110-01 the same.

[0121] Furthermore, two-body coupler 130-4b causes quantum bit device 110-4b and quantum bit device 110-01 to interact with each other through strong interaction, thereby making the state of quantum bit device 110-4b and the state of quantum bit device 110-01 the same.

[0122] Furthermore, the two-body coupler 130-5a causes the quantum bit device 110-5a and the quantum bit device 110-01 to interact with each other through strong interaction. This causes the state of the quantum bit device 110-5a to be the same as the state of the quantum bit device 110-01. In the example of FIG. 14 , the setting unit 292 sets the coupling strengths of all the two-body couplers 130 to co-coupling strengths.

[0123] Fig. 15 is a diagram showing an example of implementing the physical model in the example of Fig. 9 in a computing device 100. That is, Fig. 15 shows an example of implementing the physical model shown in Fig. 9, which corresponds to the logical model shown in Fig. 7, in a computing device 100. In the example of Fig. 15, the computing device 100 is configured to include 17 quantum bit devices 110, four four-body couplers 120, and eight two-body couplers 130.

[0124] The open circles indicate quantum bit devices 110. In the example of Fig. 15, there are quantum bit devices 110 to which logical bits are assigned and quantum bit devices 110 to which values ​​are fixed at +1. For quantum bit devices 110 to which logical bits are assigned, the index of the logical bit is shown in the open circle. For quantum bit devices 110 to which the value is fixed at +1, "+1" is written in the open circle.

[0125] The square shapes represent four-body couplers 120. The lines connecting two white circles represent two-body couplers 130. The two-body couplers 130 represented by thick lines have their interaction strength set to strong. The two-body couplers 130 represented by lines with crosses have their interaction strength set to 0.

[0126] As described above, if the two-body interaction of one of the four-body coupled physical bits is cut off and the value of that physical bit is fixed to +1, the four-body coupling can be made to function as an even-parity three-body coupling without affecting the other four-body couplings.

[0127] 15, of the four quantum bit devices 110 that are four-body coupled by the four-body coupler 120-2, the two-body interaction by the two-body coupler 130-2c that couples quantum bit device 110-2c two-body is cut off, and the value of quantum bit device 110-2c is fixed to +1.

[0128] Since the value of quantum bit device 110-2c is fixed to +1, four-body coupler 120-2 can be considered to function as an even-parity three-body coupled device that couples three quantum bit devices 110, quantum bit devices 110-2a, 110-2b, and 110-2d.

[0129] Furthermore, since the two-body interaction by the two-body coupler 130-2c is cut off, the value of the quantum bit device 110-2c is fixed to +1, which can be said to have no effect on the four-body coupling by each of the four-body couplers 120-1, 120-3, and 120-4.

[0130] When the logical model shown in Figure 8 is converted into an LHZ graph and implemented in hardware, the number of logical bits is 6, so the number of physical bits (= the number of quantum bit devices) is (6 x 5) / 2 + 4 = 19. On the other hand, in the example of Figure 15, the number of quantum bit devices is 17. In this way, it is expected that the computing device 100 can implement the target problem using a smaller number of quantum bit devices than when the LHZ model is used.

[0131] 16 is a diagram showing another example of a logic model to be implemented in the arithmetic device 100. In the example of FIG. 16, white circles represent logic bits, and the index of the logic bits is shown inside the white circles. Square shapes represent four-body bonds. Triangular shapes represent three-body bonds.

[0132] Fig. 17 is a diagram showing yet another example of implementation of a physical model in the computing device 100. Fig. 17 shows an example of a case where a physical model corresponding to the logical model shown in Fig. 16 is implemented in the computing device 100. In the example of Fig. 17, the computing device 100 is configured to include 54 quantum bit devices 110, 12 four-body couplers 120, and 34 two-body couplers 130.

[0133] The open circles indicate quantum bit devices 110. In the example of FIG. 17 , there are quantum bit devices 110 to which logical bits are assigned, quantum bit devices 110 to which values ​​are fixed at +1, and unused quantum bit devices 110. For quantum bit devices 110 to which logical bits are assigned, the index of the logical bit is shown in the open circle. For quantum bit devices 110 to which values ​​are fixed at +1, "+1" is written in the open circle. For unused quantum bit devices 110, the open circle is blank.

[0134] The square shapes represent four-body couplers 120. The lines connecting two white circles represent two-body couplers 130. The two-body couplers 130 represented by thick lines have their interaction strength set to strong. The two-body couplers 130 represented by lines with crosses have their interaction strength set to 0.

[0135] Here, consider the case where the original model shown in Fig. 16 is converted to an LHZ model and implemented in hardware. In the model shown in Fig. 16, the quantum bits indicated by white circles with three-digit numbers inside them correspond to three-body coupling, and the quantum bits indicated by white circles with four-digit numbers inside them correspond to four-body coupling. Here, the leading "0" of the number is included in the number of digits.

[0136] The original model of the model shown in Figure 16 contains three-body and four-body bonds, and cannot be converted directly to the LHZ model. To convert this model to the LHZ model, it is necessary to introduce auxiliary bits to replace the three-body and four-body bonds with two-body bonds. To replace one three-body bond with a two-body bond, one auxiliary bit is required, and to replace a four-body bond with a two-body bond, three auxiliary bits are required.

[0137] For example, if an LHZ model is generated with only two-body interactions in the original model as the target, the number of logical bits will be 15. Because an offset is applied to each auxiliary bit, the number of physical bits will be (16 × 15) / 2 + 14 = 134. On the other hand, in the example of FIG. 17, the number of quantum bit devices is 54. Thus, it is expected that the computing device 100 can implement the target problem using fewer quantum bit devices than when using the LHZ model.

[0138] Fig. 18 is a diagram showing an example of the procedure of processing performed by the arithmetic device 100. In the processing shown in Fig. 18, the setting information acquisition unit 291 acquires information for implementing a physical model of the target problem in the arithmetic device 100 (step S11).

[0139] Next, the setting unit 292 implements a physical model of the target problem in the arithmetic device 100 based on the information acquired by the setting information acquisition unit 291 in step S11 (step S12). Specifically, the setting unit 292 sets parameter values ​​of the arithmetic device 100 based on the physical model of the target problem. The setting of the parameter values ​​here can be considered as the initial setting of parameter values ​​in one solution search by quantum annealing.

[0140] Next, the operation control unit 293 controls the operation device 100 to perform one solution search using quantum annealing (step S13). For example, the operation control unit 293 calculates the value of a parameter that is to be changed over time according to time, and sets the calculated parameter value in the operation device 100.

[0141] Next, the operation control unit 293 acquires data indicating the states of the quantum bit devices 110 as a result of one solution search using quantum annealing (step S14). For example, when a predetermined time has elapsed since the start of one solution search using quantum annealing, the communication unit 210 receives a signal indicating the observation result of the state of each quantum bit device 110 from the operation apparatus 100. The operation control unit 293 extracts data indicating the state of each quantum bit device 110 from the data received by the communication unit 210.

[0142] Next, the operation control unit 293 determines whether the termination condition of quantum annealing is satisfied (step S15). As described above, the termination condition here is not limited to a specific condition. If the operation control unit 293 determines that the termination condition of quantum annealing is not satisfied (step S15: NO), the process returns to step S12.

[0143] On the other hand, if the calculation control unit 293 determines that the termination condition of quantum annealing is met (step S15: YES), the solution calculation unit 294 calculates a solution to the target problem based on the results of quantum annealing (step S16). For example, the solution calculation unit 294 determines the value of each physical bit based on the state of each quantum bit device 110 obtained for each solution search by quantum annealing. Then, the solution calculation unit 294 calculates a solution to the target problem based on the value of each physical bit. After step S16, the calculation device 100 ends the processing of FIG. 18.

[0144] As described above, the computation layer 100 includes a plurality of quantum bit devices 110, a multi-body coupler that is a three-body or higher coupled coupler, and one or more two-body couplers 130. One or more of the three or more quantum bit devices 110 coupled by the multi-body coupler are each two-body coupled to another quantum bit device 110 by the two-body coupler 130. The multi-body coupler here may be, but is not limited to, a four-body coupler 120.

[0145] According to the computing device 100, when the target problem is represented by a loosely coupled graph, it is expected that the scale of the computing device that performs quantum annealing can be made smaller than when the LHZ model is used as a physical model and implemented in hardware. The target problem is a combinatorial optimization problem that is the subject of a solution search by the computing system 1.

[0146] The computing apparatus 100 also includes a plurality of multi-body couplers. For each of the plurality of multi-body couplers, one of the quantum bit devices 110 coupled by the multi-body coupler is two-body coupled to a common quantum bit device, which is a quantum bit device 110 common to these quantum bit devices 110, by a two-body coupler 130.

[0147] According to the computing device 100, by setting the interaction strength of the two-body coupler 130 to 0, it is possible to prevent the state of the quantum bit device 110 from affecting the multi-body coupling of other multi-body couplers. The other multi-body couplers referred to here are multi-body couplers other than the multi-body coupler to which the quantum bit device 110 is coupled.

[0148] According to the computing device 100, by preventing the state of the quantum bit device 110 from affecting the multi-body coupling of other quantum bit devices and by fixing the quantum bit value indicated by that quantum bit device 110, the multi-body coupler that couples that quantum bit device 110 can function as a multi-body coupler with a smaller number of couplings. The number of couplings here refers to the number of quantum bit devices 110 to which the coupler is coupled.

[0149] Furthermore, for each of the multiple multi-body couplers, two or more of the two-body couplers 130 that couple one of the quantum bit devices 110 coupled by that multi-body coupler to the common quantum bit device cause the two quantum bit devices to interact with each other through strong interactions. The strong interaction here refers to an interaction that causes the states of the multiple quantum bit devices to be the same.

[0150] According to the computing device 100, the same logical bit can be assigned to the quantum bit devices 110 that are strongly interacting with each other via the two-body coupler 130, and the target problem can be implemented in hardware.

[0151] Furthermore, for each of the multiple multi-body couplers, the interaction strength of one or more of the two-body couplers that couple one of the quantum bit devices 110 coupled by that multi-body coupler to the common quantum bit device is set to 0.

[0152] Then, the state of one or both of the two quantum bit devices 110 coupled by the two-body coupler whose interaction strength is set to 0 is set to a predetermined state. Here, setting the state of a quantum bit device 110 to a predetermined state means setting the value of the quantum bit represented by that quantum bit device 110 to a fixed value.

[0153] According to the computing device 100, a multi-body coupler that couples quantum bit devices 110 that are set to a predetermined state can be made to function as a multi-body coupler with a smaller number of couplings.

[0154] Furthermore, for each of the two multi-body couplers, one of the quantum bit devices 110 coupled by the multi-body coupler is two-body coupled to the other quantum bit device 110 by a two-body coupler 130 .

[0155] According to the computing device 100, by setting the interaction strength of the two-body coupler 130 to 0, it is possible to prevent the state of the quantum bit device 110 from affecting the multi-body coupling of other multi-body couplers. According to the computing device 100, by preventing the state of the quantum bit device 110 from affecting the multi-body coupling of other multi-body couplers and setting the value of the quantum bit indicated by that quantum bit device 110 to a fixed value, it is possible to cause the multi-body coupler coupling that quantum bit device 110 to function as a multi-body coupler with a smaller number of couplings.

[0156] Furthermore, for each of the two multi-body couplers, one or more of the two-body couplers that two-body couple one of the quantum bit devices coupled by the multi-body coupler to another quantum bit device cause the two quantum bit devices to interact with each other through strong interaction.

[0157] According to the computing device 100, the same logical bit can be assigned to the quantum bit devices 110 that are strongly interacting with each other via the two-body coupler 130, and the target problem can be implemented in hardware.

[0158] Furthermore, for each of the two multi-body couplers, the interaction strength of one or more of the two-body couplers 130 that two-body couple one of the quantum bit devices 110 coupled by that multi-body coupler to another is set to 0.

[0159] Then, the state of either one of the two quantum bit devices 110 coupled by the two-body coupler 130, whose interaction strength is set to 0, or both of the quantum bit devices 110, is set to a predetermined state.

[0160] According to the computing device 100, a multi-body coupler that couples quantum bit devices 110 that are set to a predetermined state can be made to function as a multi-body coupler with a smaller number of couplings.

[0161] Second Embodiment Fig. 19 is a diagram showing yet another example of the configuration of a computing device according to at least one embodiment. In the configuration of a computing device 101 shown in Fig. 19, a two-body coupler 130 is added to the configuration of the computing device 100 shown in Fig. 2.

[0162] Specifically, two-body couplers 130 are added to couple two quantum bit devices 110 that are two-body coupled to the same common quantum bit device, resulting in 16 two-body couplers 130 being added: two-body couplers 130-1d2c, 130-1d4b, 130-2c5a, 130-4b5a, 130-2d3c, 130-2d5b, 130-3c6a, 130-5b6a, 130-4d5c, 130-4d7b, 130-5c8a, 130-7b8a, 130-5d6c, 130-5d8b, 130-6c9a, and 130-8b9a.

[0163] In the second embodiment, the computing system 1 includes a computing device 101 instead of the computing device 100. In other respects, the second embodiment is similar to the first embodiment.

[0164] As in the case of the arithmetic device 100, the multi-body coupler included in the arithmetic device 101 is not limited to a four-body coupler, but may be a three-body or more coupler. Furthermore, the arithmetic device 101 may be equipped with multiple types of multi-body couplers. Furthermore, the number of multi-body couplers included in the arithmetic device 101 may be two or more, and is not limited to a specific number.

[0165] 20 is a diagram showing an example in which a physical model is implemented in the arithmetic device 101. FIG. 20 shows an example in which the physical model in the example of FIG.

[0166] In the example of Fig. 20, the interaction strength of the two-body coupler 130 added to the configuration of the arithmetic device 100 in the example of Fig. 17 is set to 0. In other respects, the example of Fig. 20 is similar to the case of Fig. 17. In this way, the arithmetic device 101 can also implement a physical model similar to that of the arithmetic device 100.

[0167] Fig. 21 is a diagram showing another example in which a physical model is implemented in the computing device 101. In the example of Fig. 21, the interaction strength of each of the four-body couplers 120 is set to strong interaction. In Fig. 21, the rectangular shapes representing the four-body couplers 120 are shown with thick lines, indicating that the interaction strength of each of the four-body couplers 120 is set to strong interaction.

[0168] In this way, by setting the interaction strength of each of the four-body couplers 120 of the computing device 101 to a strong interaction, the four quantum bit devices 110 coupled by the four-body couplers 120 are in the same state. This makes it possible to implement the model represented by the King graph in the computing device 101.

[0169] Fig. 22 is a diagram showing an example of a model implemented in the arithmetic device 101. Fig. 22 shows an example of a model implemented in the arithmetic device 101 for the example of Fig. 21. In Fig. 22, the four quantum bit devices 110 coupled by the four-body coupler 120 in Fig. 21 correspond to one quantum bit. The graph shown in Fig. 22 is a King graph. In this way, according to the arithmetic device 101, it is possible to implement a model represented by a King graph in the arithmetic device 101.

[0170] As described above, the multi-body coupler causes the quantum bit devices to interact with each other through strong interactions. The two-body coupler causes the quantum bit devices to interact with each other with an interaction strength set according to the target problem. The target problem is a combinatorial optimization problem that is the subject of a solution search by the computing system 1. In the second embodiment, the computing system 1 includes a computing device 101 and a control device 200. The computing device 101 allows a model represented by a King graph to be implemented in the computing device 101.

[0171] 23 is a diagram showing another example of the configuration of a computing device according to at least one embodiment. In the configuration shown in Fig. 23, a computing device 610 includes a plurality of quantum bit devices 611, a multi-body coupler 612 that is a three-body or greater coupler, and one or more two-body couplers 613. One or more of the three or more quantum bit devices 611 coupled by the multi-body coupler 612 are each two-body coupled to another quantum bit device 611 by the two-body coupler 613.

[0172] When the target problem is represented by a loosely coupled graph, it is expected that the scale of the calculation device that performs quantum annealing can be made smaller than when the LHZ model is used as a physical model and implemented in hardware, using the calculation device 610. The target problem is a combinatorial optimization problem that is the subject of a solution search using the calculation device 610.

[0173] 24 is a diagram showing an example of the configuration of a setting device according to at least one embodiment. In the configuration shown in FIG. 24, a setting device 620 includes a setting unit 621.

[0174] In this configuration, the setting unit 621 sets parameter values ​​for the arithmetic unit. The arithmetic unit includes a plurality of quantum bit devices, a multi-body coupler that is a three-body or more coupled coupler, and one or more two-body couplers, and one or more of the three or more quantum bit devices coupled by the multi-body coupler are each two-body coupled to another quantum bit device by a two-body coupler. The setting unit 621 is an example of a setting means.

[0175] When the target problem is represented by a loosely coupled graph, it is expected that the scale of the computing device that executes quantum annealing can be made smaller than when the LHZ model is used as a physical model and implemented in hardware, using the setting device 620. The target problem is a combinatorial optimization problem that is the subject of a solution search using a computing device.

[0176] Fourth Embodiment Fig. 25 is a diagram showing an example of a procedure of a setting method according to at least one embodiment. The setting method shown in Fig. 25 includes performing setting (step S611).

[0177] In the setting (step S611), a computer sets parameter values ​​of an arithmetic unit. The arithmetic unit includes a plurality of quantum bit devices, a multi-body coupler that is a coupler with three-body or more couplings, and one or more two-body couplers. One or more of the three or more quantum bit devices coupled by the multi-body coupler are each two-body coupled to another quantum bit device by a two-body coupler.

[0178] 25, when the target problem is represented by a loosely coupled graph, it is expected that the scale of the computing device that executes quantum annealing can be made smaller than when the LHZ model is used as the physical model and implemented in hardware. The target problem is a combinatorial optimization problem that is the subject of a solution search using a computing device.

[0179] 26 is a diagram illustrating an example of a computer configuration according to at least one embodiment. In the configuration shown in FIG. 26, a computer 700 includes a CPU (Central Processing Unit) 710, a main memory device 720, an auxiliary memory device 730, and an interface 740.

[0180] One or more of the control device 200 and the setting device 620, or a part thereof, may be implemented in the computer 700. In this case, the operation of each of the above-described processing units is stored in the auxiliary storage device 730 in the form of a program. The CPU 710 reads the program from the auxiliary storage device 730, loads it into the main storage device 720, and executes the above-described processing in accordance with the program. The CPU 710 also allocates storage areas in the main storage device 720 corresponding to each of the above-described storage units in accordance with the program. Communication between each device and other devices is executed by the interface 740, which has a communication function, and performs communication under the control of the CPU 710.

[0181] When the control device 200 is implemented in a computer 700, the operations of the processing unit 290 and each of its units are stored in the form of a program in an auxiliary storage device 730. The CPU 710 reads the program from the auxiliary storage device 730, loads it into the main storage device 720, and executes the above-described processing in accordance with the program.

[0182] Furthermore, the CPU 710 allocates a storage area for the storage unit 280 in the main storage device 720 in accordance with the program. Communication with other devices by the communication unit 210 is implemented by the interface 740 having a communication function and performing communication under the control of the CPU 710. Display of images by the display unit 220 is implemented by the interface 740 having a display device and displaying various images under the control of the CPU 710. Reception of user operations by the operation input unit 230 is implemented by the interface 740 having an input device and receiving user operations under the control of the CPU 710.

[0183] When the setting device 620 is implemented in the computer 700, the operation of the setting unit 621 is stored in the form of a program in the auxiliary storage device 730. The CPU 710 reads the program from the auxiliary storage device 730, loads it into the main storage device 720, and executes the above-described processing in accordance with the program.

[0184] Furthermore, the CPU 710 allocates a storage area in the main storage device 720 for the setting device 620 to perform processing in accordance with the program. Communication between the setting device 620 and other devices is achieved by the interface 740 having a communication function and performing communication under the control of the CPU 710. Interaction between the setting device 620 and a user is achieved by the interface 740 having a display device and an input device, displaying various images under the control of the CPU 710, and accepting user operations.

[0185] Alternatively, a program for executing all or part of the processing performed by the control device 200 and the setting device 620 may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed to perform the processing of each component. The term "computer system" as used herein includes hardware such as an operating system (OS) and peripheral devices. The term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, read-only memories (ROMs), and compact disc read-only memories (CD-ROMs), as well as storage devices such as hard disks built into the computer system. The program may be designed to implement part of the aforementioned functions, or may be capable of implementing the aforementioned functions in combination with a program already stored in the computer system.

[0186] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments and includes designs within the scope of the present invention. Furthermore, the above-described embodiments may be combined with other embodiments as appropriate.

[0187] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes.

[0188] (Supplementary Note 1) A computing device comprising: a plurality of quantum bit devices; a multi-body coupler that is a coupler with three-body or greater coupling; and one or more two-body couplers, wherein one or more of the three or more quantum bit devices coupled by the multi-body coupler are each two-body coupled to another of the quantum bit devices by the two-body coupler.

[0189] (Supplementary Note 2) The computing apparatus according to Supplementary Note 1, comprising a plurality of the multi-body couplers, wherein for each of the plurality of multi-body couplers, one of the quantum bit devices coupled by the multi-body coupler is two-body coupled to a common quantum bit device that is the quantum bit device common to these quantum bit devices by the two-body coupler.

[0190] (Supplementary Note 3) The computing apparatus according to Supplementary Note 2, wherein for each of the plurality of multi-body couplers, two or more of the two-body couplers coupling one of the quantum bit devices coupled by that multi-body coupler to the common quantum bit device cause the two quantum bit devices to interact with each other through a strong interaction that brings the states of the plurality of quantum bit devices into the same state.

[0191] (Supplementary Note 4) The arithmetic apparatus according to Supplementary Note 2 or Supplementary Note 3, wherein for each of the plurality of multi-body couplers, an interaction strength of one or more of the two-body couplers coupling one of the quantum bit devices coupled by that multi-body coupler to the common quantum bit device is set to 0, and a state of one or both of the two quantum bit devices coupled by the two-body coupler whose interaction strength is set to 0 is set to a predetermined state.

[0192] (Supplementary Note 5) The arithmetic apparatus according to any one of Supplementary Notes 1 to 4, wherein for each of the two multi-body couplers, one of the quantum bit devices coupled by the multi-body coupler is two-body coupled to another quantum bit device by the two-body coupler.

[0193] (Supplementary Note 6) The computing device according to Supplementary Note 5, wherein for each of the two multi-body couplers, one or more of the two-body couplers that two-body couple one of the quantum bit devices coupled by that multi-body coupler to each other causes the two quantum bit devices to interact with each other through a strong interaction that is an interaction that brings the states of the multiple quantum bit devices into the same state.

[0194] (Supplementary Note 7) The arithmetic unit according to Supplementary Note 5 or Supplementary Note 6, wherein for each of the two multi-body couplers, an interaction strength of one or more of the two-body couplers that two-body couples one of the quantum bit devices coupled by that multi-body coupler to another is set to 0, and a state of either or both of the two quantum bit devices coupled by the two-body coupler whose interaction strength is set to 0 is set to a predetermined state.

[0195] (Supplementary Note 8) The computing device of Supplementary Note 1, wherein the multi-body coupler causes the quantum bit devices to interact with each other using a strong interaction that brings the states of the quantum bit devices into the same state, and the two-body coupler causes the quantum bit devices to interact with each other with an interaction strength that is set according to a target problem that is a combinatorial optimization problem to be solved.

[0196] (Supplementary Note 9) A setting device comprising: a plurality of quantum bit devices; a multi-body coupler that is a coupler with three-body or more coupling; and one or more two-body couplers, wherein one or more of the three or more quantum bit devices coupled by the multi-body coupler are each two-body coupled to another of the quantum bit devices by the two-body coupler; and a setting means for setting values ​​of parameters of a computing device.

[0197] (Supplementary Note 10) The setting device according to Supplementary Note 9, wherein the arithmetic unit includes a plurality of the multi-body couplers, and for each of the plurality of multi-body couplers, one of the qubit devices coupled by the multi-body coupler is bi-body coupled to a common qubit device that is the qubit device common to these qubit devices by the bi-body coupler.

[0198] (Supplementary Note 11) The setting apparatus according to Supplementary Note 10, wherein the setting means sets, for each of the plurality of multi-body couplers, a strength of interaction between two or more of the two-body couplers coupling one of the quantum bit devices coupled by that multi-body coupler to the common quantum bit device, to a strong interaction which is an interaction that brings the states of the plurality of quantum bit devices into the same state.

[0199] (Supplementary Note 12) The setting apparatus according to Supplementary Note 10 or Supplementary Note 11, wherein the setting means sets, for each of the plurality of multi-body couplers, an interaction strength of one or more of the two-body couplers that couple one of the quantum bit devices coupled by that multi-body coupler to the common quantum bit device to zero, and sets the state of either or both of the two quantum bit devices coupled by the two-body coupler whose interaction strength is set to zero to a predetermined state.

[0200] (Supplementary Note 13) The setting device according to any one of Supplementary Notes 9 to 12, wherein in the arithmetic device, for each of the two multi-body couplers, one of the quantum bit devices coupled by the multi-body coupler is two-body coupled to another quantum bit device by the two-body coupler.

[0201] (Supplementary Note 14) The setting apparatus according to Supplementary Note 13, wherein the setting means sets, for each of the two multi-body couplers, an interaction strength of one or more of the two-body couplers that two-body couple one of the quantum bit devices coupled by that multi-body coupler to a strong interaction, which is an interaction that brings the states of the multiple quantum bit devices into the same state.

[0202] (Supplementary Note 15) The setting apparatus according to Supplementary Note 13 or Supplementary Note 14, wherein the setting means sets to zero an interaction strength of one or more of the two-body couplers that two-body couple one of the quantum bit devices coupled by the two-body coupler, and sets to a predetermined state a state of either or both of the quantum bit devices coupled by the two-body coupler whose interaction strength is set to zero.

[0203] (Supplementary Note 16) The setting device described in Supplementary Note 9, wherein the setting means sets the interaction strength of the multi-body coupler to a strong interaction that brings the states of multiple quantum bit devices into the same state, and sets the interaction strength of the two-body coupler to an interaction strength that corresponds to a target problem that is a combinatorial optimization problem to be solved.

[0204] (Supplementary Note 17) A setting method including: setting, by a computer, values ​​of parameters of an arithmetic unit comprising: a plurality of quantum bit devices; a multi-body coupler which is a coupler with three-body or more coupling; and one or more two-body couplers; wherein one or more of the three or more quantum bit devices coupled by the multi-body coupler are each two-body coupled to another quantum bit device by the two-body coupler.

[0205] (Supplementary Note 18) The setting method according to Supplementary Note 17, wherein the arithmetic unit includes a plurality of the multi-body couplers, and for each of the plurality of multi-body couplers, one of the qubit devices coupled by the multi-body coupler is bi-body coupled to a common qubit device that is the qubit device common to these qubit devices by the bi-body coupler.

[0206] (Supplementary Note 19) The setting method of Supplementary Note 18, wherein setting the values ​​of the parameters of the arithmetic unit includes: for each of the plurality of multi-body couplers, setting the strength of interaction between two or more of the two-body couplers coupling one of the quantum bit devices coupled by that multi-body coupler to the common quantum bit device to a strong interaction, which is an interaction that brings the states of the plurality of quantum bit devices into the same state.

[0207] (Supplementary Note 20) The setting method of Supplementary Note 18 or Supplementary Note 19, wherein setting the values ​​of the parameters of the arithmetic unit includes: for each of the plurality of multi-body couplers, setting to zero an interaction strength of one or more of the two-body couplers that couple one of the quantum bit devices coupled by that multi-body coupler to the common quantum bit device; and setting to a predetermined state a state of either or both of the quantum bit devices coupled by the two-body coupler whose interaction strength is set to zero.

[0208] (Supplementary Note 21) The setting method according to any one of Supplementary Notes 17 to 20, wherein in the computing device, for each of the two multi-body couplers, one of the quantum bit devices coupled by the multi-body coupler is two-body coupled to another quantum bit device by the two-body coupler.

[0209] (Supplementary Note 22) The setting method according to Supplementary Note 21, wherein setting the values ​​of the parameters of the arithmetic unit includes: for each of the two multi-body couplers, setting an interaction strength of one or more of the two-body couplers that two-body couples one of the quantum bit devices coupled by that multi-body coupler to a strong interaction, which is an interaction that brings the states of the multiple quantum bit devices into the same state.

[0210] (Supplementary Note 23) The setting method according to Supplementary Note 21 or Supplementary Note 22, wherein setting the values ​​of the parameters of the arithmetic unit includes: for each of the two multi-body couplers, setting to zero an interaction strength of one or more of the two-body couplers that two-body couple one of the quantum bit devices coupled by that multi-body coupler; and setting to a predetermined state a state of either or both of the quantum bit devices coupled by the two-body coupler whose interaction strength is set to zero.

[0211] (Supplementary Note 24) The setting method according to Supplementary Note 17, wherein setting the values ​​of the parameters of the computing device includes: setting the interaction strength of the multi-body coupler to a strong interaction that brings the states of multiple quantum bit devices into the same state; and setting the interaction strength of the two-body coupler to an interaction strength according to a target problem that is a combinatorial optimization problem to be solved.

[0212] (Supplementary Note 25) A recording medium having recorded thereon a program for causing a computer to execute the steps of: setting values ​​of parameters of an arithmetic unit, the arithmetic unit comprising: a plurality of quantum bit devices; a multi-body coupler that is a coupler with three-body or more coupling; and one or more two-body couplers, wherein one or more of the three or more quantum bit devices coupled by the multi-body coupler are each two-body coupled to another quantum bit device by the two-body coupler.

[0213] (Supplementary Note 26) The storage medium according to Supplementary Note 25, wherein the arithmetic unit includes a plurality of the multi-body couplers, and for each of the plurality of multi-body couplers, one of the quantum bit devices coupled by the multi-body coupler is two-body coupled to a common quantum bit device that is the quantum bit device common to these quantum bit devices by the two-body coupler.

[0214] (Supplementary Note 27) The recording medium according to Supplementary Note 26, wherein the program causes the computer to execute the following by setting the values ​​of the parameters of the arithmetic unit: for each of the plurality of multi-body couplers, among the two-body couplers coupling one of the quantum bit devices coupled by that multi-body coupler to the common quantum bit device, setting the strength of the interaction between two or more of the two-body couplers to a strong interaction, which is an interaction that brings the states of the plurality of quantum bit devices into the same state.

[0215] (Supplementary Note 28) The recording medium according to Supplementary Note 26 or Supplementary Note 27, wherein the program causes the computer to execute the following by setting values ​​of parameters of the arithmetic unit: for each of the plurality of multi-body couplers, setting to zero an interaction strength of one or more of the two-body couplers coupling one of the quantum bit devices coupled by that multi-body coupler to the common quantum bit device; and setting to a predetermined state a state of either or both of the quantum bit devices coupled by the two-body coupler whose interaction strength is set to zero.

[0216] (Supplementary Note 29) The storage medium according to any one of Supplementary Notes 25 to 28, wherein in the computing device, for each of the two multi-body couplers, one of the quantum bit devices coupled by the multi-body coupler is two-body coupled to another quantum bit device by the two-body coupler.

[0217] (Supplementary Note 30) The recording medium according to Supplementary Note 29, wherein the program causes the computer to execute the following by setting the values ​​of the parameters of the arithmetic unit: for each of the two multi-body couplers, set the interaction strength of one or more of the two-body couplers that two-body couple one of the quantum bit devices coupled by that multi-body coupler to a strong interaction, which is an interaction that brings the states of the plurality of quantum bit devices into the same state.

[0218] (Supplementary Note 31) The recording medium according to Supplementary Note 29 or Supplementary Note 30, wherein the program causes the computer to execute the following by setting values ​​of parameters of the arithmetic unit: for each of the two multi-body couplers, setting to zero an interaction strength of one or more of the two-body couplers that two-body couple one of the quantum bit devices coupled by that multi-body coupler; and setting to a predetermined state a state of either or both of the quantum bit devices coupled by the two-body coupler whose interaction strength is set to zero.

[0219] (Supplementary Note 32) The recording medium described in Supplementary Note 25, wherein the program causes the computer to execute the following by setting values ​​of parameters of the arithmetic unit: setting the interaction strength of the multi-body coupler to a strong interaction that brings the states of multiple quantum bit devices into the same state; and setting the interaction strength of the two-body coupler to an interaction strength according to a target problem that is a combinatorial optimization problem to be solved.

[0220] The present invention may be applied to a computing device, a setting device, a setting method, and a recording medium.

[0221] REFERENCE SIGNS LIST 1 arithmetic system 100, 101, 610 arithmetic device 110, 611 quantum bit device 120 four-body coupler 130, 613 two-body coupler 130 four-body coupled block 200 control device 210 communication unit 220 display unit 230 operation input unit 280 storage unit 290 processing unit 291 setting information acquisition unit 292, 621 setting unit 293 arithmetic control unit 612 multi-body coupler 620 setting device

Claims

1. An arithmetic unit comprising: a plurality of qubit devices, a multi-body coupler that is a coupler with three or more body couplings, and one or more two-body couplers, wherein one or more of the three or more qubit devices coupled by the multi-body coupler are each two-body coupled to another qubit device by the two-body coupler.

2. The arithmetic unit according to claim 1, comprising a plurality of the multi-body couplers, and for each of the plurality of the multi-body couplers, one of the qubit devices coupled by the multi-body coupler is two-body coupled to a common qubit device that is a common qubit device common to these qubit devices by the two-body coupler.

3. The arithmetic unit according to claim 2, wherein, for each of the plurality of the multi-body couplers, among the two-body couplers coupling one of the qubit devices coupled by the multi-body coupler and the common qubit device, two or more of the two-body couplers interact two qubit devices with a strong interaction that makes the states of the plurality of qubit devices the same state.

4. The arithmetic unit according to claim 2 or claim 3, wherein, for each of the plurality of the multi-body couplers, among the two-body couplers coupling one of the qubit devices coupled by the multi-body coupler and the common qubit device, the interaction strength of one or more of the two-body couplers is set to 0, and the state of either one of the two qubit devices coupled by the two-body coupler with the interaction strength set to 0, or both of the qubit devices, is set to a predetermined state.

5. The arithmetic unit according to any one of claims 1 to 4, wherein for each of the two multi-body couplers, one of the qubit devices coupled by the multi-body coupler is two-body coupled to each other by the two-body coupler.

6. For each of the two multi-body couplers, one or more of the two-body couplers that two-body couple one of the qubit devices among the qubit devices coupled by the multi-body coupler interact two of the qubit devices with a strong interaction that is an interaction that makes the states of a plurality of qubit devices the same state. The arithmetic device according to claim 5.

7. For each of the two multi-body couplers, the interaction strength of one or more of the two-body couplers that two-body couple one of the qubit devices among the qubit devices coupled by the multi-body coupler is set to 0, and either one of the two qubit devices coupled by the two-body coupler whose interaction strength is set to 0, or the states of both qubit devices are set to a predetermined state. The arithmetic device according to claim 5 or claim 6.

8. The multi-body coupler interacts qubit devices with a strong interaction that is an interaction that makes the states of a plurality of qubit devices the same state, and the two-body coupler interacts qubit devices with an interaction strength set according to the target problem, which is the combinatorial optimization problem to be solved. The arithmetic device according to claim 1.

9. A setting device comprising: a plurality of qubit devices; a multi-body coupler that is a coupler of three-body coupling or more; one or more two-body couplers; and setting means for setting values of parameters of the arithmetic device, wherein one or more of the three or more qubit devices coupled by the multi-body coupler are each two-body coupled to other qubit devices by the two-body coupler.

10. The arithmetic device includes a plurality of the multi-body couplers, and for each of the plurality of the multi-body couplers, one of the qubit devices coupled by the multi-body coupler is two-body coupled by the two-body coupler with a common qubit device that is a common qubit device among these qubit devices. The setting device according to claim 9.

11. The setting means, for each of the plurality of the multi-body couplers, sets the interaction strength of two or more of the two-body couplers that couple one of the quantum bit devices coupled by the multi-body coupler and the common quantum bit device to a strong interaction which is an interaction that makes the states of the plurality of quantum bit devices the same state. The setting device according to claim 10.

12. The setting means, for each of the plurality of the multi-body couplers, sets the interaction strength of one or more of the two-body couplers that couple one of the quantum bit devices coupled by the multi-body coupler and the common quantum bit device to 0, and sets the state of either one or both of the two quantum bit devices coupled by the two-body coupler whose interaction strength is set to 0 to a predetermined state. The setting device according to claim 10 or 11.

13. A setting method including a computer setting the value of a parameter of an arithmetic device, the arithmetic device including: a plurality of quantum bit devices; a multi-body coupler which is a coupler of three-body coupling or more; and one or more two-body couplers, wherein one or more of the three or more quantum bit devices coupled by the multi-body coupler are each two-body coupled to another quantum bit device by the two-body coupler.

14. The arithmetic device includes a plurality of the multi-body couplers, and for each of the plurality of the multi-body couplers, one of the quantum bit devices coupled by the multi-body coupler is two-body coupled by the two-body coupler to a common quantum bit device which is a quantum bit device common to these quantum bit devices. The setting method according to claim 13.

15. Setting the value of the parameter of the arithmetic unit includes, for each of the plurality of multi-body couplers, setting the interaction strength of two or more of the two-body couplers that couple one of the qubit devices coupled by the multi-body coupler and the common qubit device to a strong interaction that is an interaction that makes the states of the plurality of qubit devices the same state. The setting method according to claim 14.

16. Setting the value of the parameter of the arithmetic unit includes, for each of the plurality of multi-body couplers, setting the interaction strength of one or more of the two-body couplers that couple one of the qubit devices coupled by the multi-body coupler and the common qubit device to 0, and setting the state of either one or both of the two qubit devices coupled by the two-body coupler whose interaction strength is set to 0 to a predetermined state. The setting method according to claim 14 or 15.

17. A recording medium recording a program for causing a computer to execute setting the value of the parameter of an arithmetic unit, the arithmetic unit including a plurality of qubit devices, a multi-body coupler that is a coupler of three-body coupling or more, and one or more two-body couplers, and one or more of the three or more qubit devices coupled by the multi-body coupler being two-body coupled to other qubit devices by the two-body coupler.

18. The recording medium according to claim 17, wherein the arithmetic unit includes a plurality of the multi-body couplers, and for each of the plurality of the multi-body couplers, one of the qubit devices coupled by the multi-body coupler is two-body coupled by the two-body coupler with a common qubit device that is a common qubit device among these qubit devices.

19. The program causes the computer to execute, by setting the value of the parameter of the arithmetic unit, for each of the plurality of multi-body couplers, among the two-body couplers that couple one of the quantum bit devices among the quantum bit devices coupled by the multi-body coupler and the common quantum bit device, setting the interaction strength of two or more of the two-body couplers to a strong interaction that is an interaction that makes the states of the plurality of quantum bit devices the same state, the recording medium according to claim 18.

20. The program causes the computer to execute, by setting the value of the parameter of the arithmetic unit, for each of the plurality of multi-body couplers, setting the interaction strength of one or more of the two-body couplers that couple one of the quantum bit devices among the quantum bit devices coupled by the multi-body coupler and the common quantum bit device to 0, and setting the state of either one or both of the two quantum bit devices coupled by the two-body coupler whose interaction strength is set to 0 to a predetermined state, the recording medium according to claim 18 or 19.

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