Density inhomogeneities and Rashba spin-orbit coupling interplay in oxide interfaces
Density inhomogeneities and Rashba spin-orbit coupling interplay in oxide interfaces
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DOI：
10.1016/j.jpcs.2017.09.013
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发表时间：
2019-05-01
影响因子：
4
通讯作者：
Seibold, G.
中科院分区：
文献类型：
--
作者：
Bovenzi, N.;Caprara, S.;Seibold, G.
越来越多的证据表明，在某些绝缘氧化物（如LaAlO3/SrTiO3和LaTiO3/SrTiO3）的界面上形成的二维电子气体（2DEG）是强烈不均匀的。电子密度的不均匀分布伴随着在界面处约束电子的（自洽）电场的不均匀分布。这种非均匀的横向电场反过来诱导了非均匀的Rashba自旋轨道耦合（RSOC）。在介绍性总结了两种可能导致电子相分离的机制后，我们引入了一个现象学模型来描述密度依赖的RSOC及其后果。除了本身是不均匀性或电荷密度波的可能来源外，密度依赖的RSOC还引起了有趣的物理效应，如不均匀自旋电流分布和不均匀量子霍尔态的发生，手性“边缘”态发生在2DEG的主体中。非均匀RSOC也可以用于自旋电子器件，因为它可以用来产生无序鲁棒自旋霍尔效应。
There is steadily increasing evidence that the two-dimensional electron gas (2DEG) formed at the interface of some insulating oxides like LaAlO3/SrTiO3 and LaTiO3/SrTiO3 is strongly inhomogeneous. The inhomogeneous distribution of electron density is accompanied by an inhomogeneous distribution of the (self-consistent) electric field confining the electrons at the interface. In turn this inhomogeneous transverse electric field induces an inhomogeneous Rashba spin-orbit coupling (RSOC). After an introductory summary on two mechanisms possibly giving rise to an electronic phase separation accounting for the above inhomogeneity, we introduce a phenomenological model to describe the density-dependent RSOC and its consequences. Besides being itself a possible source of inhomogeneity or charge density waves, the density-dependent RSOC gives rise to interesting physical effects like the occurrence of inhomogeneous spin-current distributions and inhomogeneous quantum-Hall states with chiral "edge" states taking place in the bulk of the 2DEG. The inhomogeneous RSOC can also be exploited for spintronic devices since it can be used to produce a disorder-robust spin Hall effect.