News release overview
Hitachi Proposes a New Qubit Control Method Suited to Large-Scale Integration Toward Practical Realization of a Silicon Quantum Computer
Through joint research with the Institute for Molecular Science, accelerate development of a quantum operating system
Tokyo, June 12, 2023 – Hitachi, Ltd. (TSE: 6501) today announced that it has proposed and confirmed the effectiveness of a "shuttling qubit" method for efficiently controlling qubits,*1 aimed at practical implementation of a silicon quantum computer. The key to practical implementation of a quantum computer is to achieve high integration on a scale of 1 million qubits or more, while implementing error correction*2 on this scale. A silicon quantum computer, the object of Hitachi's research and development, is seen as more readily scalable compared to the superconducting approach on which research is currently further along. Factors standing in the way of such large-scale integration, however, include the need to connect operation and readout circuits to all qubits, which are normally placed in a fixed location, and the occurrence of crosstalk (error) between adjacent qubits.
In the newly proposed shuttling qubit approach, areas for operation, readout, and other control are assigned in advance and qubits can be freely moved across these areas. This eliminates the need for connecting operation and readout circuits to all qubits, simplifying the silicon device interconnect structure, while also enabling the impact of crosstalk to be minimized by shuttling adjacent qubits aside during operations.
Additionally, Hitachi has begun developing a quantum operating system suited to control of a quantum computer, including one adopting the proposed technology. This development is being carried out jointly with a research group led by Professor Kenji Ohmori of the Institute for Molecular Science in the Inter-University Research Institute Corporation National Institutes of Natural Sciences (hereinafter, "Institute for Molecular Science"). This collaborative research is aimed at accelerating studies on large-scale integration toward early practical implementation of a quantum computer.
*1 Qubit: A qubit (or quantum bit) is the basic unit of information in quantum computing. Making use of the superposition principle of quantum mechanics, a qubit can represent states with both 0 and 1 in any proportion.
*2 Error correction: Technology for correcting errors occurring in the process of quantum calculation. One logical qubit is represented by multiple qubits (redundancy) and the redundant qubits are used to detect/estimate error.
