Combinatorial optimization problem processing apparatus, combinatorial optimization problem processing method, and program

A combinatorial optimization problem processing apparatus comprising:

• a quantum annealer configured to acquire, using an annealing scheme, a candidate for a first solution in an alternate optimization algorithm in which a first optimization processing and a second optimization processing are repeated until a predetermined end condition is satisfied;
• a processor;
• and
• a storage medium having computer program instructions stored thereon, wherein the computer program instructions, when executed by the processor, perform processing of:
• acquiring a second solution;
• and
• acquiring a candidate for an immediately preceding first solution when the predetermined end condition is satisfied, as a candidate for a solution of a combinatorial optimization problem that is an analysis target,
• wherein the first solution is a variable q that satisfies a first predetermined condition regarding a maximum value of a root finding target partition function and that is acquired by the first optimization processing, the first optimization processing acquiring a value of the variable q satisfying the first predetermined condition, the variable q being a sole independent variable of the first optimization processing, the root finding target partition function being a partition function whose Hamiltonian is an analysis target function, the analysis target function being a function representing the combinatorial optimization problem and is a function including third- or higher-order terms of the variable q, the Hamiltonian being represented by a predetermined integral representation using a variable X, the Hamiltonian being represented by a sum of a first equation that includes only second- or lower-order terms of the variable q and a second equation not including the variable q, the second solution being the variable X that satisfies a second predetermined condition regarding a maximum value of the root finding target partition function and that is acquired by the second optimization processing, the second optimization processing acquiring a value of the variable X satisfying the second predetermined condition, the variable X being the sole independent variable of the second optimization processing,
• wherein the quantum annealer includes a plurality of physical quantum bits, and
• wherein the quantum annealer is configured to measure quantum states of the physical quantum bits to acquire the candidate for the first solution.