Physical properties and control of topological materials strongly coupled with light in non-equilibrium and excited states

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K03695
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13020:Semiconductors, optical properties of condensed matter and atomic physics-related
• Research Institution: University of Tsukuba
• Principal Investigator: Hino Ken-ichi 筑波大学, 数理物質系, 教授 (90228742)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: トポロジカル物質 / トポロジカル絶縁体 / ディラック半金属 / ワイル半金属 / フロケ状態 / フロケエンジニアリング / 光制御 / 非平衡系ダイナミクス

Outline of Final Research Achievements

Recently, the studies toward the exploration and applications of topological materials with novel features have been conducted widely and vigorously in the world. Physical properties of these materials are attributed to topological order protected by symmetry that results from bulk band inversion leading to twisted band structures. Differing from conventional studies of topological properties in equilibrium, in this study, one makes theoretical investigations of topological order and the associated phase transitions formed in laser-driven quasi-two-dimensional and three-dimensional topological semimetals in non-equilibrium. To be specific, one finds novel phenomena of optically controlled surface states, chirality, magnetic properties, and so on.

Free Research Field

光物性理論

Academic Significance and Societal Importance of the Research Achievements

連続波レーザーのような周期的外場によって様々な結晶の状態を制御する研究領域はフロケエンジニアリングと呼ばれ、平衡系では到達困難な多彩な物質相の発現および新規物性の実現が期待される。光照射により生成したトポロジカル半金属相に関する本研究はその一環であり、トポロジーと対称性をキーワードとする非平衡系物理における未知な学理の探究は学術的に大いに意義がある。さらに、超高速な光制御による新規デバイスの開発に向けた応用研究に関しても潜在的な意義がある。