RIKEN Establishes Center for Quantum Computing
Towards Developing a Hub for Quantum Technology Innovation

RIKEN established the new RIKEN Center for Quantum Computing (RQC) on April 1. The center will work towards the development of quantum computers, including hardware, middleware, and software, under the government's quantum technology innovation strategy, as a hub for quantum computer development. During his speech at the opening, RIKEN President Hiroshi Matsumoto said, "I believe that the opening of RQC on April 1 was timely in that it is the starting date for the Sixth Science, Technology and Innovation Basic Plan. We intend to support the center as much as possible. Furthermore, RIKEN will play a role as a central organization supporting the eight locations positioned for the quantum technology strategy, and we hope to contribute to achieving that strategy."

With regards to his management policy, Dr. Yasunobu Nakamura, Director of the RQC, added, "We will carry out research and development for the realization of quantum computers, covering all layers of technology including hardware, middleware, and software. We will work with a diverse range of personnel to achieve a breakthrough in every aspect from fundamental research to application, and from theory to experiment. We will carry out the research and development to contribute to society as an open center through wide-ranging collaboration between industry, academia, and government, as well as both globally and domestic. We will also train the personnel who will shoulder the next generation of the quantum technology field through research and development." A close look at the research team at the center reveals a high level of diversity, with over half the team and unit leaders coming from the University of Tokyo, Osaka University, Tokyo University of Science, and the University of Basel, with various expertise in atoms and electrons, semiconductors, theory, superconductivity, and optics. According to Dr. Nakamura, "The fascinating thing about quantum information is that there is a common language that connects the fields. New ideas are born from this common language, even across completely different physics fields. For example, there are many situations where superconducting quantum computing theory can be applied to optical quantum computing, so I expect that our diverse mix of personnel will lead to innovation."

The RQC will engage in four general areas of research. The first is the development of hardware, middleware, and software for launching an actual superconducting quantum computer. This will include addressing the development of a process for the scalable 2D integration of superconducting qubit, a quantum error correction code for fault-tolerant quantum computation, control electronics for large-scale quantum integration circuits, and NISQ circuits for the installation of quantum-classical hybrid optimization algorithms. According to Dr. Nakamura, the researchers have "currently completed a 16-qubit chip and are evaluating its performance, but work will start on the development of a 64 qubit chip within the year. In addition to increasing the number of bits, we will also need to develop a variety of other technologies simultaneously for quantum gate control."

The center will also work on research and development with the goal of realizing a fault-tolerant optical quantum computer. Specific challenges include measurement-induced optical quantum computation based on continuous quantum teleportation technology, increased scale through optical signal time-division multiplexing, and developing quantum optics for optical fiber in communication wavelengths, as well as loss reduction and stability.

Further research at the center will include the search for an NISQ algorithm that can be implemented on the quantum computer hardware to be built in the near future, and theoretical research on future fault-tolerant quantum computing. This will include fault-tolerant quantum computing theory, research on algorithms for NISQ machines (such as condensed matter physics, quantum chemistry, and machine learning), the use of HPC and quantum computers to evaluate algorithm performance, exploring applications for quantum simulations, and applications for machine learning and AI in quantum physics and quantum information science research.

Fundamental research will also be carried out in the various physical sciences on high precision quantum control and observation technology, both essential for building quantum computers. The themes that will be addressed include "bosonic codes," a low-overhead error correction code in superconducting resonators, semiconductor spin qubit integration, electron spin state control on helium liquid surfaces, and cooled atom quantum simulations in triangular optical lattices.

While the main goal will be to create a superconducting quantum computer, the center will also work on other methods, theories, and basic research. According to Dr. Nakamura, "The important goal for the time being will be the development of a functioning superconducting quantum computer. I myself achieved superconducting qubits more than 20 years ago, but I was unable to predict the advancements we would be making today. Google has proven the existence of quantum transcendence, but there is still a long road ahead of us before we can apply it. And although we are approaching a precision of 0.999 at several tens of bits, that level is essentially just a demonstration. We intend to build a functioning machine using an expandable design."

Collaboration Center Established by RIKEN and Fujitsu Limited

In addition, RIKEN and Fujitsu have also established the RIKEN RQC-Fujitsu Collaboration Center within the RQC. This center will integrate RQC's development of a superconducting quantum computer with Fujitsu's computing technology with the aim of jointly creating a functioning superconducting quantum computer with 1,000 qubits and software.

Fujitsu is currently applying quantum computing technology to solve complex problems faced in the actual workplace, in such fields as pharmaceuticals and logistics, by using their Digital Annealer technology for solving combinatorial optimization problems as quickly as possible, but they also announced a new research and development strategy in October last year to work on overall quantum computing, including quantum devices, algorithms, and applications. As part of the announcement, they stated that they would be conducting joint research with Osaka University, Delft University of Technology, and Quantum Benchmark Inc., and established the collaboration center with the RIKEN RQC towards the actual development of a functioning superconducting quantum computer.

The collaboration center will operate over the next four years. According to Managing Director Hirotaka Hara, "We will carry out fundamental research to achieve 1,000 qubits over those four years. The operation of the center will be further extended according to the research and development progress, shifting toward developing a functional machine from the fifth year. We will start with a staff of 10 people in the first year, and gradually add more from the second year. The center will also serve as a bridge with user companies."