The spin-orbit interaction is popular for spintronic applications since, through the mechanism of spin-dependent asymmetric scattering, spin currents are generated from charge currents (spin Hall effect) or charge currents are generated from spin currents (inverse spin Hall effect). The discovery of spin, a century ago, relied on a magnetic field gradient to separate opposite spins; this mechanism has received scant attention as a means for generating spin and charge currents in semiconductors. Through the derivation of a set of coupled spin-charge drift-diffusion equations, our paper shows that magnetic field gradients can be used to generate charge currents from nonequilibrium spin polarization in confined solid state systems. We predict, in GaAs, a longitudinal “Stern-Gerlach” voltage. Nonintuitively, we find the spin diffusion length is reduced by the magnetic gradient, which has ramifications for interpreting spin transport experiments. This suppression is understood by invoking the idea of cocurrent and countercurrent exchange, which is a concept found in fields as disparate as animal physiology and thermal engineering.

中文翻译：

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通过半导体中的逆斯特恩-格拉赫效应产生充电电流

自旋轨道相互作用在自旋电子学应用中很受欢迎，因为通过自旋相关的不对称散射机制，自旋电流是由充电电流（自旋霍尔效应）产生的，或者充电电流是由自旋电流（逆自旋霍尔效应）产生的。一个世纪前，自旋的发现依赖于磁场梯度来分离相反的自旋。作为在半导体中产生自旋和充电电流的一种手段，这种机制并没有受到足够的关注。通过推导一组耦合自旋电荷漂移扩散方程，我们的论文表明磁场梯度可用于在受限固态系统中从非平衡自旋极化产生电荷电流。我们预测砷化镓中存在纵向“斯特恩-格拉赫”电压。与直觉不同的是，我们发现自旋扩散长度因磁梯度而减小，这对于解释自旋输运实验具有影响。这种抑制可以通过并流和逆流交换的概念来理解，这是在动物生理学和热工程等不同领域中发现的概念。