Control of band structure and emergent novel phenomena based on band topology
| Project/Area Number |
26287062
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Partial Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Condensed matter physics I
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥13,390,000 (Direct Cost: ¥10,300,000、Indirect Cost: ¥3,090,000)
Fiscal Year 2017: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2016: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2015: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2014: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
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| Keywords | トポロジカル絶縁体 / ワイル半金属 / トポロジー / スピンエレクトロニクス / 物性理論 / 表面状態 / 輸送現象 |
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| Outline of Final Research Achievements |
We constructed general theories on phase transitions of topological materials. For example, we showed that a closing of a gap of an insulator without inversion symmetry always leads to a topological semimetal. We also constructed a theory on superlattices of topological semimetals, and a theory on surface-state dispersions of Weyl semimetals. We also proposed various new topological materials, such as tellurium at high pressure as a Weyl semimetal, and calcium at high pressure as a nodal-line semimetal. We also unveiled new physical phenomena of topological materials. We proposed a concept of interfacial symmetries and revealed appearance of novel interfacial states. We also showed an anomalous dielectric response of bilayer graphene ribbons by an interlayer bias voltage.
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| Academic Significance and Societal Importance of the Research Achievements |
トポロジカル物質は、その電子状態がトポロジーで特徴づけられることはわかっているが、それらの物質が固有に持っている、通常の物質と異なる物性、またどのような物質がトポロジカル物質になるかという物理的解釈はいまだ不足している。本研究成果は、その点についての一般論を構築することで、今度のトポロジカル物質の探索や実験に資する。例えばトポロジカル物質の新規提案は実験的な検証へと直結していくことが期待できる。またトポロジカル物質の相転移の理論や超格子の理論などは、広い範囲のトポロジカル物質に適用されるため、今後の本分野への波及効果も大きい。
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Report
(5 results)
Research Products
(63 results)
