Domain wall in a quantum anomalous Hall insulator as a magnetoelectric piston
Domain wall in a quantum anomalous Hall insulator as a magnetoelectric piston
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DOI：
10.1103/physrevb.94.020411
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发表时间：
2015-12
影响因子：
3.7
通讯作者：
P. Upadhyaya;Y. Tserkovnyak
中科院分区：
文献类型：
--
作者：
P. Upadhyaya;Y. Tserkovnyak
本文从理论上研究了动态磁化织构与拓扑绝缘体界面诱导的量子反常霍尔绝缘体态的磁电耦合。特别是，我们提出的量子反常霍尔绝缘体的磁配置的域壁，当接触的电水库，作为一个磁电活塞。移动的畴壁在闭合电路中的电引线之间泵送电荷电流，而施加电偏压引起畴壁的往复运动。这种活塞式的作用是通过有限反射的电荷载流子通过手性模式压印的域壁。此外，我们发现，当与最近发现的自旋-轨道扭矩诱导的畴壁运动在重金属相比，反射系数起着有效的自旋霍尔角的作用，建议的电控制畴壁的效率。量化，这个有效的自旋霍尔角被发现接近普适值2，提供了一个有效的方案来重新配置可能的存储器和逻辑应用的畴壁手性互连。
We theoretically study the magnetoelectric coupling in a quantum anomalous Hall insulator state induced by interfacing a dynamic magnetization texture to a topological insulator. In particular, we propose that the quantum anomalous Hall insulator with a magnetic configuration of a domain wall, when contacted by electrical reservoirs, acts as a magnetoelectric piston. A moving domain wall pumps charge current between electrical leads in a closed circuit, while applying an electrical bias induces reciprocal domain-wall motion. This pistonlike action is enabled by a finite reflection of charge carriers via chiral modes imprinted by the domain wall. Moreover, we find that, when compared with the recently discovered spin-orbit torque-induced domain-wall motion in heavy metals, the reflection coefficient plays the role of an effective spin-Hall angle governing the efficiency of the proposed electrical control of domain walls. Quantitatively, this effective spin-Hall angle is found to approach a universal value of 2, providing an efficient scheme to reconfigure the domain-wall chiral interconnects for possible memory and logic applications.