2026-10-15 理化学研究所
図1 シリコン量子ビットデバイスの模式図
＜関連情報＞
- https://www.riken.jp/press/2026/20261015_2/index.html
- https://www.nature.com/articles/s41567-026-03466-2
スピン量子ビットアレイにおける同時高忠実度単一量子ビットゲート Simultaneous high-fidelity single-qubit gates in a spin qubit array
Yi-Hsien Wu, Leon C. Camenzind, Patrick Bütler, Ik Kyeong Jin, Akito Noiri, Kenta Takeda, Takashi Nakajima, Takashi Kobayashi, Giordano Scappucci, Hsi-Sheng Goan & Seigo Tarucha
Nature Physics Published:15 October 2026
DOI:https://doi.org/10.1038/s41567-026-03466-2
Abstract
Silicon spin qubits offer a promising path to scalable quantum computing due to their compatibility with industrial semiconductor manufacturing. A key requirement for scaling quantum processors is the ability to perform high-fidelity operations in parallel across many qubits. However, simultaneous control remains a major challenge in silicon devices, as fidelities typically degrade under parallel operation. Here we identify microwave-drive-induced a.c.-Stark shifts as the dominant source of this degradation in a five-qubit silicon spin array. We address this by introducing a scalable mitigation protocol based solely on pairwise phase calibrations. Using tailored control pulses on a shared control line, we achieve primitive X and Y gate fidelities well above 99.99% for each qubit individually, with some approaching 99.999%. Furthermore, these fidelities are preserved above 99.99% during simultaneous operation of up to three qubits. During parallel five-qubit operation, fidelities remain above the widely targeted fault-tolerant threshold of 99.9%. By maintaining high-fidelity control during simultaneous operation, shared qubit-control lines can support the development of large-scale semiconductor quantum processors.
