What are the Main Areas of Research in Japanese Quantum Computer R&D?

Quantum Computing R&D Is Steadily Progressing Around the World

What is the current state of research and development (R&D) on quantum computing aimed at full-scale practical application? Promoting the development of quantum computers requires the development of hardware (i.e. machines) and software/algorithms to operate the hardware in addition to basic theoretical research.

Quantum computing R&D is steadily progressing in advanced countries around the world. In hardware development, optical and ion trap methods are attracting increased interest in addition to superconducting methods, long considered the mainstream approach for realizing qubits. As for software, there are emerging trends and efforts being made towards the full-scale use of quantum computers, for instance, by leveraging hybrid methods that make good use of both classical and quantum computers or by adopting Python as a standard programming language. Moreover, in October 2019 Google’s claim of “quantum supremacy” became a hot topic, essentially claiming the ability of its quantum computer to process and execute certain computations much faster than classical devices*1. Quantum supremacy is an important milestone in the R&D of quantum computers, and expectations are growing worldwide for their practical application.

In line with these increasing expectations, major movement in quantum computing R&D has been witnessed in Japan. This article discusses the companies involved in R&D, their areas of focus, and governmental policies to support quantum technology R&D in Japan.

Quantum Computer R&D Strategies of Japanese Companies

The current research divisions in domestic companies can be divided into the following three groups.

Group (1) provides optimization solutions that constitute the strength of quantum annealing machines and support their development. Examples of Japanese companies in this group are Jij, Fixstars, and NTT Data. Also, optimization calculations using quantum annealing machines have been brought into the spotlight by different companies. Examples include portfolio optimization in the finance sector, material design applications in the chemical field and route optimization to avoid traffic congestion. Joint research and realization of solutions have been promoted in a range of areas. The point of these efforts lies in determining how to transform real world problems into combinatorial optimization problems and how to lower technical barriers to facilitate the use of quantum annealing machines. The team led by Masayuki Ohzeki, an Associate Professor at Tohoku University and Tokyo Institute of Technology, is well known for leading joint research with various companies using quantum annealing machines.

Group (2) includes companies developing algorithms and software for quantum annealing machines and quantum gate computers and providing consultation to organizations wanting to use them. Examples of companies in this group include MDR and QunaSys in addition to Jij and Fixstars, which are also engaged group (1) activities. The development of algorithms requires not only a specialized understanding of quantum physics but also a high level of ingenuity to successfully perform calculations on quantum computers. Furthermore, an understanding of information engineering and computer science is essential. Most software in this area is made available as open source, suggesting that companies are aiming to expand the community by having as many users as possible using their software.

For group (3), major Japanese vendors are the main players. Quantum annealing machines are being developed by NEC and the National Institute of Advanced Industrial Science and Technology (AIST), while pseudo-quantum computers (i.e. simulated annealing machines) by NEC, Toshiba, Hitachi, and Fujitsu. Pseudo-quantum computers are not quantum machines in the true sense of the word, but are classified as classical computers specializing in optimization calculations. Given that existing technologies can be applied, the application of these computers can be anticipated in the near future, but the short-term challenge is determining to what extent actual problems can be solved. In the mid to long term, their value will be questioned throughout the introduction of practical genuine quantum computers.

The following figure roughly portrays the situation of the aforementioned Japanese companies. In the figure, the axes are set for quantum gate/quantum annealing and software/hardware. While there are Japanese companies working in quantum computing R&D in areas (1) to (3) , the “quantum gate × hardware” area enclosed by the dotted line is limited to research by universities and research institutes*2. Currently, there are no Japanese companies in this area at a large-scale. Overseas giants such as Google, IBM, and Alibaba have already invested heavily in this area to build an international R&D infrastructure, and hence Japanese businesses wanting to join the market will probably require considerable resolve.

Government Policies Supporting Quantum Technology R&D

Government policies supporting quantum technologies, including quantum computers, have appeared in recent years. Quantum technology is positioned as a target field in the Cabinet Office's “Integrated Innovation Strategy”*3 and “Moonshot Research and Development Program,” which targets the creation of disruptive innovation*4. In addition, the Ministry of Education, Culture, Sports, Science and Technology's “Quantum Leap Flagship Program (Q-LEAP)*5” is also underway.

The budget allocated to quantum technology innovation strategy in FY2020 is about 21.5 billion yen, up considerably from the previous fiscal year (approximately 16 billion yen). In terms of annual budget, it is comparable to the U.S. (approximately 28 billion yen, maximum 140 billion yen over five years) and the EU (approximately 12.5 billion yen approximately 125 billion yen over 10 years)*6.

Quantum Technology Innovation Strategy, as a core policy, lays out objectives to promote the practical application and commercialization of both hardware and software for quantum annealing. For quantum gate, the strategy provides objectives to promote research focusing on hardware superconductivity and to drive the practical application of software in the short and medium term.

Rising Expectations for Acceleration of Quantum Computing R&D in Japan Through New Collaborations

This article has introduced the areas of quantum computing R&D where Japanese companies are involved and national policies have been created. These areas have witnessed the development of businesses using quantum annealing machines and providing software that targets general users. On the other hand, there are only a handful of Japanese companies involved in developing quantum gate computers.

Government budget allocations for quantum technology is increasing across the world. In the future, it will be increasingly important for the government to continue supporting research with a long-term perspective while private businesses from different industries will engage with this field as users and to collaborate internationally with leading overseas universities, research institutes, and companies.

In recent years, such trends have increased in both the public and private sectors through collaboration with the U.S. and Europe. Examples include the EU-USA-Japan International Symposium on Quantum Technology*7 at the national level and IBM Q Network*8 and Microsoft Quantum Network*9 at the private level. Examples of industry-academia partnerships include Keio University's IBM Q Network @ Keio University*10, Tohoku University's T-QARD*11, and the University of Tokyo's partnership agreement with IBM*12. There are many other efforts to note, such as QPARC, an industry-academia collaborative community established by the startup QunaSys*13.

In this way, there is much to anticipate in quantum computing R&D in Japan thanks to steady research and the development of various collaborations. It should be interesting to watch future trends and further progress toward the making of a society that fully utilizes quantum computers.