Gravitational field theory for topological thermal transport phenomena

2022 Fiscal Year Final Research Report

• Project/Area Number: 17K17604
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Mathematical physics/Fundamental condensed matter physics; Condensed matter physics I
• Research Institution: Kyushu University (2022); Tohoku University (2019-2021); Institute of Physical and Chemical Research (2017-2018)
• Principal Investigator: Nakai Ryota 九州大学, 理学研究院, 特任助教 (30638987)
• Project Period (FY): 2017-04-01 – 2023-03-31
• Keywords: 熱伝導 / 重力場 / 非相反応答

Outline of Final Research Achievements

Thermal transport theory of electrons from the viewpoint of quantum mechanics was studied. A new formula for estimating the thermal conductivity was found by exploiting the relationship between thermal conduction and coordinate transformations. This formula links the quantum mechanical property of the boundary conditions of the wavefunction and the thermal conductivity. A similar formula for the electrical conduction has been known as the Kohn's formula, and hence our formula can be viewed as the thermal version of the Kohn's formula. The theory of nonreciprocity of the thermal and thermoelectric conductions was also studied.

Free Research Field

物性理論

Academic Significance and Societal Importance of the Research Achievements

固体物質の熱伝導現象の中でも近年特に量子力学的性質が強く現れる現象が実験物理の分野でも重要になりつつある。本研究で導入された公式は広く一般の量子系に適用可能であるため、熱伝導現象の量子力学的側面の理解が深まることが期待される。また非相反熱応答現象は別の言葉で言うと順方向と逆方向で熱の流れやすさが異なるという整流効果である。電気伝導の整流効果を利用したダイオードやトランジスタのように熱の非相反性の強い物質が開発されれば、固体物質中の熱を自在に操ることができ、排熱の有効利用などの熱に関する問題の解決手段となることが期待される。