Thermoelectric transport in topological insulators
Thermoelectric transport in topological insulators
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DOI：
10.1088/0268-1242/27/12/124005
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发表时间：
2012-12
影响因子：
1.9
通讯作者：
Ryuji Takahashi;S. Murakami
中科院分区：
文献类型：
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作者：
Ryuji Takahashi;S. Murakami
对拓扑绝缘体中的热电输运进行了理论研究。TI在二维中具有无隙边缘态，并且在三维中具有表面态。这两种状态都具有无背散射的性质，并且在掺杂杂质的情况下它们保持无隙。特别是，在二维TI的边缘状态形成完美的导电通道。在这项研究中，我们计算了系统尺寸依赖的热电性能在二维TI，并评估的声子的边缘态的非弹性散射长度，它影响的热电性能敏感。我们还研究了三维（3D）TI的热电输运，并与二维进行比较。在二维和三维TI中，热电现象中的表面/边缘和体输运之间存在竞争。由于杂质的存在，3D TI中的表面输运与体输运相比相对较弱。此外，我们还研究了有间隙的三维TI的薄板几何形状，并显示在有间隙的系统的品质因数的大值。这一结果与之前的工作是一致的。
Thermoelectric transport in topological insulators (TIs) is theoretically studied. TIs have gapless edge states in two dimensions, and do surface states in three dimensions. Both of the states have backscattering-free nature, and they remain gapless in the presence of nonmagnetic impurities. In particular, the edge states in two-dimensional TIs form perfect conducting channels. In this study, we calculate system-size dependence of thermoelectric properties in two-dimensional TIs, and evaluate the inelastic scattering length of the edge states by phonons, which affects the thermoelectric properties sensitively. We also study thermoelectric transport in three-dimensional (3D) TIs and compare with two dimensions. In both two- and three-dimensional TIs, there is a competition between the surface/edge and bulk transports in the thermoelectric phenomena. The surface transport in 3D TIs is relatively weak compared with the bulk transport due to impurities. Furthermore, we also study gapped 3D TIs in thin slab geometry and show large values of the figure of merit in the gapped system. This result is consistent with the previous work.