In 1999, NEC developed a superconducting qubit for use in gate-type quantum computers. Since then NEC has applied the technology in the research and development of a quantum annealing machine.
NEC has developed a four qubit unit cell of the LHZ scheme. This enables scaling to multiple fully-connected logical qubits utilizing superconducting parametron and circuit coupling technology.
NEC has solved small-scale combinatorial optimization problems via quantum annealing using this new technology, and has also developed a 3D structure technology that connects many LHZ scheme unit cells arranged in a tile pattern with external devices.
By replicating the unit cell in a tile pattern, it is possible to create a structure where many qubits are logically connected to each other, whilst maintaining the features of the superconducting parametron that allow it to perform calculations with high accuracy.
NEC’s development of a quantum annealing machine using superconducting parametrons was a project commissioned by the New Energy and Industrial Technology Development Organization (NEDO).
NEC is currently conducting R&D to improve the integration of superconducting parametrons in a fully connected architecture, with the aim of realising quantum annealing machines by 2023.