2019 Fiscal Year Final Research Report
Transport phenomena induced by the interplay of topology and symmetry in topological superconductors
| Project/Area Number |
16K05448
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | Osaka University |
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Principal Investigator |
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| Project Period (FY) |
2016-04-01 – 2020-03-31
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| Keywords | トポロジカル超伝導 / 超流動 / 集団励起 |
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| Outline of Final Research Achievements |
In this work, we have unveiled novel transport phenomena in topological superconductors. We have found that there exist new bosonic modes, the nematicity mode and chiral Higgs mode, in nematic superconductors. It has been demonstrated that such bosonic modes play crucial roles in EM absorption and dynamical spin susceptibility. The quasiclassical transport theory provides a powerful and tractable tool for studying static and dynamical phenomena in superconductors and superfluids. However, it has been recognized that the theory does not incorporate the contributions of geometric phases such Berry phase, which play key roles in transport in topological materials. In this work, we have succeeded in developing the quasiclassical theory to incorporate the contributions of geometric phases. Using the augmented theory, we have discovered the exotic transport in Weyl superconductors, such as torsional chiral magnetic effect and negative thermal magnetoresistivity.
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| Free Research Field |
物性理論
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| Academic Significance and Societal Importance of the Research Achievements |
本課題の研究成果は大きく2つに分けられる：(1)トポロジカル超伝導に有効な準古典理論の拡張と(2)トポロジカルな物質観を中性子星へ展開したことである．本課題において(1)を用いて既に「捻れ場由来のカイラル磁気効果」や「負の熱磁気抵抗効果」など新しい輸送現象を見出したが，さらに今後のトポロジカル超伝導性に由来した新奇な交差応答やトポロジカル超伝導をプラットフォームとしたスピントロニクス研究などへの展開が期待される．また，トポロジカルな物質観を中性子に展開することで，中性子星の異常な冷却機構や巨大磁場の起源、さらにはパルサーグリッチといった未解決問題への新たな切り口となると期待する．
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