Kazuki Takabatake

We develop and provide a quantum-inspired optimization solution, SQBM+.

Many problems in society and industry, such as optimization of financial transactions, optimization of industrial robot operations, optimization of travel and power transmission routes, and molecular design for drug discovery, often lead to "combinatorial optimization problems," where the emphasis is on finding the optimal solution from a vast number of alternatives. SQBM+ is software that makes it possible to obtain highly accurate approximate solutions as an excellent solution to such problems in a short time.

Fixstars Amplify has been a long-standing supporter of performing calculations using SQBM+ as the solver, but it was my first personal experience utilizing it as part of the use case development initiatives within Q-STAR (Japan Council for the Creation of New Industries through Quantum Technology).

The two specific problems we worked on were as follows:

• Formulate real-world problems in the field of physical chemistry as QUBOs with several thousand variables and solve them mainly with SQBM+.
• Solve already formulated Ising problems in tens of thousands of variables derived from real-world problem in the field of finance, mainly with SQBM+.

After actually using Fixstars Amplify, I found it very convenient to be able to try various Ising machines just by switching the solver part. Especially for large-scale problems, there are differences in calculation results depending on the characteristics of each machine. I was able to notice these phenomena because of the Fixstars Amplify environment, which allows us to easily try various machines with a single formulation (Python program).

Also, as a detail of the SDK, the fact that it supports mutual conversion between QUBO and Ising formats was helpful. This is useful when you want to solve a problem created in one format with a solver for the other format. It is also a feature that can reduce the burden of formulating problem, since which format is more natural depends on the problem.

It is also important for programmers to have a good reference and demo program on the web. I was able to learn how to use them successfully in a very short time.

This time, we have used SQBM+ and Fixstars Amplify in combination for a short period of time and found them to be highly compatible. We would like to recommend SQBM+ and Fixstars Amplify to our customers when we have the opportunity in the future.

* All information presented in this article is based on data available at the time of the interview (May 2023).