Thickness Dependence of the Quantum Anomalous Hall Effect in Magnetic Topological Insulator Films

Xiao Feng; Yang Feng; Jing Wang; Yunbo Ou; Zhenqi Hao; Chang Liu; Zuocheng Zhang; Liguo Zhang; Chaojing Lin; Jian Liao; Yongqing Li; Li-Li Wang; Shuai-Hua Ji; Xi Chen; Xucun Ma; Shou-Cheng Zhang; Yayu Wang; Ke He; Qi-Kun Xue

doi:10.1002/adma.201600919

Thickness Dependence of the Quantum Anomalous Hall Effect in Magnetic Topological Insulator Films

Adv Mater. 2016 Aug;28(30):6386-90. doi: 10.1002/adma.201600919. Epub 2016 May 11.

Authors

Xiao Feng^{1

2}, Yang Feng¹, Jing Wang^{3

4}, Yunbo Ou², Zhenqi Hao¹, Chang Liu¹, Zuocheng Zhang¹, Liguo Zhang^{1

2}, Chaojing Lin², Jian Liao², Yongqing Li², Li-Li Wang^{1

5}, Shuai-Hua Ji^{1

5}, Xi Chen^{1

5}, Xucun Ma^{1

5}, Shou-Cheng Zhang³, Yayu Wang^{1

5}, Ke He^{1

5}, Qi-Kun Xue^{1

5}

Affiliations

¹ State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, 100084, China.
² Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
³ Department of Physics, Stanford University, Stanford, CA, 94305-4045, USA.
⁴ State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai, 200433, China.
⁵ Collaborative Innovation Center of Quantum Matter, Beijing, 100084, China.

PMID: 27166762
DOI: 10.1002/adma.201600919

Abstract

The evolution of the quantum anomalous Hall effect with the thickness of Cr-doped (Bi,Sb)2 Te3 magnetic topological insulator films is studied, revealing how the effect is caused by the interplay of the surface states, band-bending, and ferromagnetic exchange energy. Homogeneity in ferromagnetism is found to be the key to high-temperature quantum anomalous Hall material.

Keywords: magnetic topological insulators; quantum anomalous Hall effect; thickness dependence; thin films.