Quantum anomalous Hall effect driven by magnetic proximity coupling in all-telluride based heterostructure
Quantum anomalous Hall effect driven by magnetic proximity coupling in all-telluride based heterostructure
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DOI：
10.1063/1.5111891
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发表时间：
2019-08
影响因子：
4
通讯作者：
R. Watanabe;R. Yoshimi;M. Kawamura;M. Mogi;A. Tsukazaki;Xiuzhen Yu;K. Nakajima;Kei S. Takahashi;M. Kawasaki;Y. Tokura
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文献类型：
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作者：
R. Watanabe;R. Yoshimi;M. Kawamura;M. Mogi;A. Tsukazaki;Xiuzhen Yu;K. Nakajima;Kei S. Takahashi;M. Kawasaki;Y. Tokura
量子反常霍尔效应（QAHE）是一种奇异的量子现象，起源于样品边缘的无耗散手性通道。虽然已经在磁性掺杂的拓扑绝缘体（TI）中观察到QAHE，但是利用相邻铁磁体层在TI表面上的磁性邻近效应可以通过打开具有比掺杂系统中更少无序的交换能隙来提供QAHE的替代方法。然而，一个有利的异质界面，实现QAHE的基础上的磁邻近效应的工程仍然有待实现。在这里，我们报告的QAHE在非磁性TI和铁磁绝缘体（FMI）的邻近耦合系统的观察。我们已经设计了三明治异质结构的（Zn，Cr）Te/（Bi，Sb）2 Te 3/（Zn，Cr）Te，满足两个先决条件出现的QAHE;形成一个相当大的交换间隙在TI表面状态和调整的费米能量到交换间隙。在所有碲化物基异质结构中的有效邻近耦合，如这里所展示的，将使得能够实现与铁磁性、铁电性、超导性等耦合的多功能定制拓扑材料的现实设计。
The quantum anomalous Hall effect (QAHE) is an exotic quantum phenomenon originating from dissipation-less chiral channels at the sample edge. While the QAHE has been observed in magnetically doped topological insulators (TIs), exploiting magnetic proximity effect on the TI surface from adjacent ferromagnet layers may provide an alternative approach to the QAHE by opening an exchange gap with less disorder than that in the doped system. Nevertheless, the engineering of a favorable heterointerface that realizes the QAHE based on the magnetic proximity effect remains to be achieved. Here, we report on the observation of the QAHE in a proximity coupled system of non-magnetic TI and ferromagnetic insulator (FMI). We have designed sandwich heterostructures of (Zn,Cr)Te/(Bi,Sb)2Te3/(Zn,Cr)Te that fulfills two prerequisites for the emergence of the QAHE; the formation of a sizable exchange gap at the TI surface state and the tuning of the Fermi energy into the exchange gap. The efficient proximity coupling in the all-telluride based heterostructure as demonstrated here will enable a realistic design of versatile tailor-made topological materials coupled with ferromagnetism, ferroelectricity, superconductivity, and so on.