Development of heavy-hole spin qubit in germanium and its optimization by contorling spin-orbit interaction

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15114
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 28020:Nanostructural physics-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Mizokuchi Raisei 東京工業大学, 工学院, 特任助教 (90848772)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ゲルマニウム / 量子ドット

Outline of Final Research Achievements

The utilization of heavy-hole spins in germanium nanostructures holds the potential to achieve simple yet high-speed and long-lived qubits. In this study, our objective is to realize such quantum bits by focusing on the implementation of germanium quantum dot structures and the development of qubit measurement techniques. Specifically, we initiated the fabrication process of quantum devices using Ge/SiGe heterostructures and successfully created Hall bar devices and quantum dot devices. Furthermore, we constructed a measurement system for high-speed readout using RF waves, aiming towards the realization of qubits.

Free Research Field

ナノ構造デバイス

Academic Significance and Societal Importance of the Research Achievements

本研究では、ゲルマニウム中の重い正孔に着目し量子ビットの実現を目指すという、量子コンピュータ実現に向けた基盤的な研究を行った。この中で、ゲルマニウム量子デバイスの作製に成功している。これは、今後の高性能なゲルマニウムスピン量子ビットの実現に貢献する重要な成果である。並行して、高速なスピン読み出しを可能にするRF反射測定の最適化条件の確立という、他のスピン量子ビット系へも適用できる学術的意義の大きい成果も挙げている。