Enhancing performance of quantum control techniques for electron spin qubits in silicon quantum dots

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K14640
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13020:Semiconductors, optical properties of condensed matter and atomic physics-related
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Noiri Akito 国立研究開発法人理化学研究所, 創発物性科学研究センター, 基礎科学特別研究員 (40804042)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 量子ビット / 量子ドット / 電子スピン

Outline of Final Research Achievements

We developed device fabrication techniques to fabricate stable and tunable silicon quantum dots with a high yield. We realized a high-fidelity single-qubit control in single electron spin qubits and also demonstrated a single-qubit operation for a singlet-triplet qubit. Then we focused on improving a performance of a two-qubit gate between two single electron spin qubits. We carefully designed the device to make the two-qubit gate faster and as a result, we succeeded in enhancing a two-qubit gate fidelity. Furthermore, we established a new technique to control a two-qubit coupling and drastically enhanced on off ratio of the two-qubit coupling.

Free Research Field

半導体物理

Academic Significance and Societal Importance of the Research Achievements

シリコンスピン量子コンピュータでは、量子ビットの種類、2量子ビット操作の実装手法など基本動作においても複数の候補があり、その優位性はいまだ決まっていない。本研究では、異種スピン量子ビット複合系の実現可能性や既存の2量子ビット操作手法における高忠実操作の実現、およびより拡張性に優れる新しい2量子ビット操作手法の開発を行うことで、各手法の性能や相性を明らかにし、今後のシリコンスピン量子コンピュータの開発方針に指針を与えた。