Shift charge and spin photocurrents in Dirac surface states of topological insulator
Shift charge and spin photocurrents in Dirac surface states of topological insulator
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DOI：
10.1103/physrevb.95.035134
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发表时间：
2017-01-23
影响因子：
3.7
通讯作者：
Nagaosa, Naoto
中科院分区：
文献类型：
--
作者：
Kim, Kun Woo;Morimoto, Takahiro;Nagaosa, Naoto
凝聚态物质中光电流的产生是光伏和光电子应用的主要兴趣。位移电流是一种非线性光响应，作为铁电材料中体光伏效应的主要参与者，近年来引起了人们的广泛关注。在三维拓扑绝缘体 Bi2X3 (X = Te, Se) 中，我们发现具有六边形翘曲项的狄拉克表面态支持线性偏振光的移动电流。此外，我们通过引入时间反演对称性破缺扰动来研究狄拉克表面态中出现的“移位自旋流”。 Bi2Te3 的移位电荷和自旋电流密度大小的估计值分别为 0.13I(0) 和 0.40I(0) (nA/m)，光强度 I-0 测量单位为 (W/m(2))，这可以提供一种有效生成这些电流的有用方法。
The generation of photocurrent in condensed matter is of main interest for photovoltaic and optoelectronic applications. Shift current, a nonlinear photoresponse, has attracted recent intensive attention as a dominant player of bulk photovoltaic effect in ferroelectric materials. In three-dimensional topological insulators Bi2X3 (X = Te, Se), we find that Dirac surface states with a hexagonal warping term support shift current by linearly polarized light. Moreover, we study "shift spin current" that arises in Dirac surface states by introducing time-reversal symmetry breaking perturbation. The estimate for the magnitudes of the shift charge and spin current densities are 0.13I(0) and 0.40I(0) (nA/m) for Bi2Te3 with the intensity of light I-0 measured in (W/m(2)), respectively, which can offer a useful method to generate these currents efficiently.