Current-Induced Spin Polarization in Nonmagnetic Semiconductors
Current-Induced Spin Polarization in Nonmagnetic Semiconductors
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非磁性半导体中电流引起的自旋极化
DOI：
10.1007/s10948-018-4918-y
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发表时间：
2018
影响因子：
1.8
通讯作者：
M. Flatté
中科院分区：
文献类型：
--
作者：
Y. Qi;M. Flatté
自发电子自旋极化在半导体中的使用避免了来自磁性材料的电子自旋注入的传输挑战以及密集阵列中的小磁体的堆积约束。虽然对电流自发自旋极化的研究主要集中在自旋-轨道场及其效应上，但从原理上讲，运动的电子气可以不稳定地通过与载流子自旋无关的载流子散射过程形成自旋极化分布。对于这种没有自旋-轨道相互作用的电流诱导的自旋极化，两个所需的要素是（1）存在内置的空间变化电场，其自然形成（如在古恩效应中）或外部的（如在具有空间依赖掺杂的结中）和（2）能量依赖的载流子散射过程。由于这种效应不需要自旋-轨道相互作用，它应该发生在像硅这样缺乏零场自旋分裂的反转对称材料和像氧化锌和氮化镓这样缺乏显著自旋-轨道相互作用的材料中。
The use of spontaneous electron spin polarization in nonmagnetic semiconductors avoids the transport challenges of electron spin injection from magnetic materials as well as packing constraints of small magnets in a dense array. Although the focus of rearch on the spontaneous spin polarization of electrical current has been on spin-orbit fields and their effects, in principle a moving electron gas can be unstable to forming spin-polarized distributions via carrier scattering processes that are independent of the carrier spin. The two required elements for such current-induced spin polarization without spin-orbit interactions are (1) the presence of built-in spatially-varying electric fields, either naturally forming (as in the Gunn effect) or extrinsic (as in a junction with spatially dependent doping) and (2) energy-dependent carrier scattering processes. As spin-orbit interactions are not required for this effect, it should occur in inversion-symmetric materials like silicon that lack zero-field spin splittings and materials like zinc oxide and gallium nitride that lack significant spin-orbit interactions.