Control of single magnetic spin in a semiconductor dot and its application

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K18988
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 28:Nano/micro science and related fields
• Research Institution: University of Tsukuba
• Principal Investigator: Kuroda Shinji 筑波大学, 数理物質系, 教授 (40221949)
• Project Period (FY): 2018-06-29 – 2022-03-31
• Keywords: 量子ドット / 単一スピン / 交換相互作用 / 光学ポンピング

Outline of Final Research Achievements

We have clarified various aspects of the behavior of a single Cr atom in a CdTe self-assembled dot. We observed the splitting of the exciton emission spectrum due to the exchange interaction with a single Cr spin in the dot, and showed that the distribution of each Cr spin state can be controlled by resonant excitation to the split emission lines. We observed the decay of the distribution of specific Cr spin states generated under resonant excitation (optical pumping) and clarified the transition process between Cr spin states as the origin of the decay. In addition, we found an emission spectrum with a similar shape to that of the exchange splitting of Cr spins, but with different characteristics such as linear polarization properties, which is attributed to the valence fluctuation splitting of Cr ions located near the dots.

Free Research Field

スピントロニクス

Academic Significance and Societal Importance of the Research Achievements

本研究の成果により、CdTe自己形成ドット中の単一Crスピンの種々の特性を明らかにすることができた。特に、共鳴励起の手法により特定のCrスピンの分布が制御できることを示した。この成果は、ドット中の単一Crスピンを量子ビットとして用いた量子情報処理への応用の可能性の探索という点で学術的、社会的意義を有すると考えられる。