Topological Hall Effect in a Topological Insulator Interfaced with a Magnetic Insulator
Topological Hall Effect in a Topological Insulator Interfaced with a Magnetic Insulator
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DOI：
10.1021/acs.nanolett.0c03195
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发表时间：
2021-01-13
期刊：
影响因子：
10.8
通讯作者：
Wu, Mingzhong
中科院分区：
文献类型：
--
作者：
Li, Peng;Ding, Jinjun;Wu, Mingzhong
与磁性绝缘体（MI）对接的拓扑绝缘体（TI）可以具有反常霍尔效应（AHE）、量子AHE和拓扑霍尔效应（THE）。然而，最近的研究表明，在TI/MI异质结构共存的磁相可能会导致AHE相关的响应，类似于THE，但实际上不是。这封信报道了一个真正的在TI/MI结构，只有一个磁相的THE。该结构在T = 2-3 K的温度范围内显示出THE，在T = 80-300 K的温度范围内显示出AHE。在T = 3-80 K，这两种效应共存，但表现出相反的温度依赖性。控制测量，计算和模拟一起表明，所观察到的THE起源于skyrmions，而不是两个AHE响应的共存。skyrmions是由于在界面处的Dzyaloshinskiii-Moriya相互作用（Dzyaloshinskii-Moriya）而形成的;估计的Dzyaloshinski-Moriya强度大大高于重金属系统。
A topological insulator (TI) interfaced with a magnetic insulator (MI) may host an anomalous Hall effect (AHE), a quantum AHE, and a topological Hall effect (THE). Recent studies, however, suggest that coexisting magnetic phases in TI/MI heterostructures may result in an AHE-associated response that resembles a THE but in fact is not. This Letter reports a genuine THE in a TI/MI structure that has only one magnetic phase. The structure shows a THE in the temperature range of T = 2-3 K and an AHE at T = 80-300 K. Over T = 3-80 K, the two effects coexist but show opposite temperature dependencies. Control measurements, calculations, and simulations together suggest that the observed THE originates from skyrmions, rather than the coexistence of two AHE responses. The skyrmions are formed due to a Dzyaloshinskii-Moriya interaction (DMI) at the interface; the DMI strength estimated is substantially higher than that in heavy metal-based systems.