Novel fermiology by current-induced phenomena

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K20889
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 13:Condensed matter physics and related fields
• Research Institution: Tohoku University
• Principal Investigator: Aoki Dai 東北大学, 金属材料研究所, 教授 (30359541)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: フェルミオロジー / 量子振動 / 強相関トポロジカル超伝導

Outline of Final Research Achievements

A major breakthrough in research occurred with the unexpected discovery of superconductivity in UTe2 and its new phenomena. As a result, extensive research has been focused on UTe2. Notable achievements include the discovery of multiple superconductivity in UTe2 and the observation of field-induced superconductivity under pressure. Additionally, we successfully achieved the growth of the world's highest-purity single crystals and achieved the first-ever observation of quantum oscillation effects (dHvA effect). It was found that UTe2 has two types of two-dimensional Fermi surfaces and forms an extremely heavy electron state. Furthermore, results suggesting a mixed valence state were obtained through comparison with band calculations. The obtained results have led to new research projects on current-induced phenomena utilizing FIB techniques.

Free Research Field

物性物理

Academic Significance and Societal Importance of the Research Achievements

本研究は、電流誘起による新現象をフェルミオロジーの観点から明らかにする挑戦的課題であったが、研究期間中の予期せぬブレークスルーによって、UTe2のフェルミオロジーを含む研究に大きく舵を切ることになった。その結果、多くの顕著な成果が生まれた。量子コンピューターへの応用も期待されるなど、高い関心と激しい国際競争の中、世界をリードする研究成果が得られた。