拓扑绝缘体
异质结
材料科学
凝聚态物理
磁场
范德瓦尔斯力
量子反常霍尔效应
分子束外延
拓扑(电路)
绝缘体(电)
霍尔效应
量子霍尔效应
图层(电子)
外延
纳米技术
光电子学
物理
量子力学
分子
组合数学
数学
作者
Nan Liu,Xuefan Niu,Yuxin Liu,Qinghua Zhang,Lin Gu,Yongqing Li,Jing Teng
出处
期刊:Physical Review Materials
[American Physical Society]
日期:2020-09-22
卷期号:4 (9)
被引量:1
标识
DOI:10.1103/physrevmaterials.4.094204
摘要
Constructing heterostructures of a topological insulator (TI) with an undoped magnetic insulator (MI) is a clean and versatile approach to break the time-reversible symmetry in the TI surface states. Despite a lot of efforts, the strength of interfacial magnetic proximity effect (MPE) is still too weak to achieve the quantum anomalous Hall effect and many other topological quantum phenomena. Recently, a new approach based on intercalation of atomic layers of MI, referred to as magnetic extension, was proposed to realize strong MPE [2D Mater. 4, 025082(2017)]. Motivated by this proposal, here, we study a magnetic extension system prepared by molecular beam epitaxy growth of MnSe thin films on topological insulator (Bi,Sb)2Te3. Direct evidence is obtained for intercalation of MnSe atomic layer into a few quintuple layers of (Bi,Sb)2Te3, forming either a double magnetic septuple layer (SL) or an isolated single SL at the interface, where one SL denotes a van der Waals building block consisting of B-A-B-Mn-B-A-B (A=Bi1-xSbx, B= Te1-ySey). The two types of interfaces (namely TI/mono-SL and TI/bi-SL) have different MPE, which is manifested as distinctively different transport behaviors. Specifically, the mono-SL induces a spinflip transition with a sharp change at small magnetic field in the anomalous Hall effect of TI layers, while the bi-SL induces a spin-flop transition with a slow change at large field. Our work demonstrates a useful platform to realize the full potential of the magnetic extension approach for pursuing novel topological physics and related device applications.
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