Giant Spin Rotation in the Junction between a Normal Metal and a Quantum Spin Hall System
Giant Spin Rotation in the Junction between a Normal Metal and a Quantum Spin Hall System
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DOI：
10.1103/physrevlett.102.166801
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发表时间：
2009-04-24
影响因子：
8.6
通讯作者：
Nagaosa, Naoto
中科院分区：
文献类型：
--
作者：
Yokoyama, Takehito;Tanaka, Yukio;Nagaosa, Naoto
我们从理论上研究了普通金属和以参数 M 为特征的绝缘体之间的连接处的反射问题，该绝缘体是 M > 0 的常见绝缘体或 M < 0 的量子自旋霍尔系统。反射处的自旋旋转角 α 是 M 和从界面法线测量的入射角 θ 的函数。 α在量子临界点M=0和theta=0附近显示出丰富的结构；即，在量子自旋霍尔情况 M < 0 的入射角下，α 可以大到类似于 pi，因为螺旋边缘模式共振地增强了自旋旋转，这可用于映射螺旋边缘模式的能量色散。作为一个实验相关系统，我们还研究了量子-自旋-霍尔-法向-金属-量子-自旋-霍尔三层结中的自旋旋转效应。
We study theoretically the reflection problem in the junction between a normal metal and an insulator characterized by a parameter M, which is a usual insulator for M > 0 or a quantum-spin-Hall system for M < 0. The spin rotation angle alpha at the reflection is obtained as a function of M and the incident angle theta measured from the normal to the interface. The alpha shows rich structures around the quantum critical point M=0 and theta=0; i.e., alpha can be as large as similar to pi at an incident angle in the quantum spin Hall case M < 0 because the helical edge modes resonantly enhance the spin rotation, which can be used to map the energy dispersion of the helical edge modes. As an experimentally relevant system, we also study the spin rotation effect in quantum-spin-Hall-normal-metal-quantum-spin-Hall trilayer junction.