Circular photogalvanic effect on topological insulator surfaces: Berry-curvature-dependent response
Circular photogalvanic effect on topological insulator surfaces: Berry-curvature-dependent response
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DOI：
10.1103/physrevb.83.035309
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发表时间：
2011-01-18
影响因子：
3.7
通讯作者：
Hosur, Pavan
中科院分区：
文献类型：
--
作者：
Hosur, Pavan
我们从理论上研究了拓扑绝缘体表面态的光学响应，特别是圆偏振光产生螺旋度相关的直流电流。有趣的是，由于带间跃迁，主导电流由表面带的Berry曲率控制。这将光电流和Berry曲率之间的联系扩展到了准经典近似之外，而准经典近似已经被证明是成立的。给出了拓扑绝缘体Bi2Se3的(111)面的显式表达式，当表面的旋转对称性被面内磁场或应变破坏时，我们发现了显著的螺旋度相关的光电流。此外，主导电流随着时间线性增长，直到发生散射，这提供了一种确定散射时间的方法。在表面产生的DC自旋也是由时间线性的Berry曲率相关的贡献决定的。
We study theoretically the optical response of the surface states of a topological insulator, especially the generation of helicity-dependent direct current by circularly polarized light. Interestingly, the dominant current, due to an interband transition, is controlled by the Berry curvature of the surface bands. This extends the connection between photocurrents and Berry curvature beyond the quasiclassical approximation, where it has been shown to hold. Explicit expressions are derived for the (111) surface of the topological insulator Bi2Se3, where we find significant helicity-dependent photocurrents when the rotational symmetry of the surface is broken by an in-plane magnetic field or a strain. Moreover, the dominant current grows linearly with time until a scattering occurs, which provides a means for determining the scattering time. The dc spin generated on the surface is also dominated by a linear-in-time, Berry curvature-dependent contribution.