2015 Fiscal Year Final Research Report
Theory on the thermoelectricity in the Dirac electron systems
Project/Area Number |
25870231
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Research Category |
Grant-in-Aid for Young Scientists (B)
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Allocation Type | Multi-year Fund |
Research Field |
Condensed matter physics II
Condensed matter physics I
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Research Institution | The University of Electro-Communications |
Principal Investigator |
Fuseya Yuki 電気通信大学, 情報理工学(系)研究科, 准教授 (00377954)
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Project Period (FY) |
2013-04-01 – 2016-03-31
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Keywords | ディラック電子系 / 熱電効果 / スピン軌道結合 |
Outline of Final Research Achievements |
Spin-Hall conductivity (SHC) and diamagnetism are investing for the Dirac electron systems. An exact formula that relates the SHC and the diamagnetism is found. Based on this theoretical finding, the magnitude of SHC in Bi turns out to be about 100 times larger than that of Pt. The ratio of the Zeeman splitting to the cyclotron energy, Mzc, characterizes the relative strength of the spin-orbit coupling in crystal. Mzc has been quantified during the past five decades experimentally. Theoretically, however, it has not been examined in detail so far and there was a longstanding mystery about Mzc. We examined Mzc on the basis of the relativistic k.p theory for thermoelectric materials, such as Bi, PbTe and SnTe. We found a solution to the half-a-century-old puzzle for Bi. We also found that M=1 is obtained just at the band inversion point, where the transition to the topological insulator can occur. By using this property, one can detect the transition point only with the bulk measurements.
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Free Research Field |
物性理論
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