Phonon angular momentum and anomalous phonon response

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K13494
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Tohoku University
• Principal Investigator: Nii Yoichi 東北大学, 金属材料研究所, 助教 (80708488)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: フォノン角運動量 / 対称性の破れ / 非相反性 / 表面弾性波

Outline of Final Research Achievements

Phonon angular momentum plays an important role as a pseudo-spin degree of freedom in phononic system. According to analogy of electronic system, number of novel phonon responses may emerge by taking this concept into account. Here we report several results such as phononic Rashba state in a chiral magnet, phonon Hall effect in Tb oxides, and nonreciprocal thermal current in a multiferroic.

Free Research Field

磁性

Academic Significance and Societal Importance of the Research Achievements

本研究によりフォノン角運動量という概念が新奇フォノン物性の理解に極めて重要であることを示した。また、本研究を基軸として例えばトポロジカルなフォノン状態など、いくつもの新奇物性を開拓する道筋が示された。これらの成果によって将来的には新機能を備えた音波や熱デバイスの実現へと繋がると期待される。