Ballistic spin transport in exciton gases
Ballistic spin transport in exciton gases
复制标题
DOI：
10.1103/physrevb.88.195309
复制
发表时间：
2013-11-21
影响因子：
3.7
通讯作者：
Butov, L. V.
中科院分区：
文献类型：
--
作者：
Kavokin, A. V.;Vladimirova, M.;Butov, L. V.
传统的自旋电子学依赖于电荷载流子的自旋输运，例如半导体晶体中的电子。实现远程电子自旋输运的挑战包括由于电子散射引起的快速自旋弛豫。在激子器件中，自旋电流由电中性的玻色子准粒子（激子或激子-极化激元）携带，从而可以有效地抑制散射和自旋弛豫。它们可以形成在宏观距离上携带自旋的相干量子液体。付出的代价是玻色子自旋载流子的有限寿命。我们提出了激子弹道自旋输运理论，该理论可应用于一系列支持玻色子自旋输运的系统，特别是耦合量子威尔斯中的间接激子。我们描述了电子和空穴的自旋轨道相互作用对激子自旋的影响，解释了外磁场引起的塞曼效应以及激子共振的长程和短程交换分裂.我们还考虑了激子输运的非线性制度，并讨论了激子自旋电流，极化电流和自旋电导率的定义。
Traditional spintronics relies on spin transport by charge carriers, such as electrons in semiconductor crystals. The challenges for the realization of long-range electron spin transport include rapid spin relaxation due to electron scattering. Scattering and, in turn, spin relaxation can be effectively suppressed in excitonic devices where the spin currents are carried by electrically neutral bosonic quasiparticles: excitons or exciton-polaritons. They can form coherent quantum liquids that carry spins over macroscopic distances. The price to pay is a finite lifetime of the bosonic spin carriers. We present the theory of exciton ballistic spin transport which may be applied to a range of systems supporting bosonic spin transport, in particular to indirect excitons in coupled quantum wells. We describe the effect of spin-orbit interaction for the electron and the hole on the exciton spin, account for the Zeeman effect induced by external magnetic fields and long-range and short-range exchange splittings of the exciton resonances. We also consider exciton transport in the nonlinear regime and discuss the definitions of the exciton spin current, polarization current, and spin conductivity.