Observation of Quantum Anomalous Hall Effect and Exchange Interaction in Topological Insulator/Antiferromagnet Heterostructure
Observation of Quantum Anomalous Hall Effect and Exchange Interaction in Topological Insulator/Antiferromagnet Heterostructure
复制标题
拓扑绝缘体/反铁磁体异质结构中量子反常霍尔效应和交换相互作用的观察
DOI：
10.1002/adma.202001460
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发表时间：
2020-07-21
影响因子：
29.4
通讯作者：
Wang, Kang L.
中科院分区：
文献类型：
--
作者：
Pan, Lei;Grutter, Alexander;Wang, Kang L.
量子反常霍尔绝缘体与磁性有序材料的集成提供了额外的自由度，通过该自由度可以控制产生的奇异量子态。本文报道了在反铁磁绝缘体Cr2O_3上生长的掺磁拓扑绝缘体中量子反常霍尔效应的实验观测。用场致冷相关磁学和偏振中子反射法研究了两种材料之间的交换耦合。这两种技术都揭示了Cr2O_3的反铁磁性有序与磁性拓扑绝缘体之间强烈的界面相互作用，当样品在平面外磁场下场冷时，表现为交换偏置，而当系统在薄膜平面内磁化时，表现为交换弹簧状的磁深度分布。这些结果表明，反铁磁性绝缘体是控制拓扑绝缘体薄膜的磁序和拓扑有序的合适候选者。
Integration of a quantum anomalous Hall insulator with a magnetically ordered material provides an additional degree of freedom through which the resulting exotic quantum states can be controlled. Here, an experimental observation is reported of the quantum anomalous Hall effect in a magnetically‐doped topological insulator grown on the antiferromagnetic insulator Cr2O3. The exchange coupling between the two materials is investigated using field‐cooling‐dependent magnetometry and polarized neutron reflectometry. Both techniques reveal strong interfacial interaction between the antiferromagnetic order of the Cr2O3 and the magnetic topological insulator, manifested as an exchange bias when the sample is field‐cooled under an out‐of‐plane magnetic field, and an exchange spring‐like magnetic depth profile when the system is magnetized within the film plane. These results identify antiferromagnetic insulators as suitable candidates for the manipulation of magnetic and topological order in topological insulator films.