Deduction of pure spin current from the linear and circular spin photogalvanic effect in semiconductor quantum wells
Deduction of pure spin current from the linear and circular spin photogalvanic effect in semiconductor quantum wells
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DOI：
10.1103/physrevb.75.045339
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发表时间：
2007-01-01
影响因子：
3.7
通讯作者：
Shen, Shun-Qing
中科院分区：
文献类型：
--
作者：
Zhou, Bin;Shen, Shun-Qing
通过求解半导体光学布洛赫方程，研究了具有结构反转非对称性的二维电子系统中的自旋光电流效应。结果表明，线偏振光由于Rashba自旋轨道耦合，可以向自旋分裂导带注入纯自旋电流，而圆偏振光则注入自旋相关的光电流.我们建立了圆偏振光斜入射时产生的光电流与线偏振光垂直入射时产生的纯自旋电流之间的显式关系，从而可以从实验测量的自旋光电流中推导出自旋电流的振幅。该方法为定量研究半导体中的自旋输运提供了一个自旋电流源。
We study the spin photogalvanic effect in a two-dimensional electron system with structure-inversion asymmetry by means of solution of the semiconductor optical Bloch equations. It is shown that linearly polarized light may inject a pure spin current into spin-splitting conduction bands due to Rashba spin-orbit coupling, while circularly polarized light may inject a spin-dependent photocurrent. We establish an explicit relation between the photocurrent caused by oblique incidence of circularly polarized light and the pure spin current caused by normal incidence of linearly polarized light such that we can deduce the amplitude of the spin current from the experimentally measured spin photocurrent. This method may provide a source of spin current to study spin transport in semiconductors quantitatively.