Enhancing the Quantum Anomalous Hall Effect by Magnetic Codoping in a Topological Insulator |
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| Authors: | Yunbo Ou Chang Liu Gaoyuan Jiang Yang Feng Dongyang Zhao Weixiong Wu Xiao‐Xiao Wang Wei Li Canli Song Li‐Li Wang Wenbo Wang Weida Wu Yayu Wang Ke He Xu‐Cun Ma Qi‐Kun Xue |
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| Affiliation: | 1. State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, China;2. Collaborative Innovation Center of Quantum Matter, Beijing, P. R. China;3. Department of Physics and Astronomy, School of Arts and Sciences, Rutgers University, Piscataway, NJ, USA |
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| Abstract: | The quantum anomalous Hall (QAH) effect, which has been realized in magnetic topological insulators (TIs), is the key to applications of dissipationless quantum Hall edge states in electronic devices. However, investigations and utilizations of the QAH effect are limited by the ultralow temperatures needed to reach full quantization—usually below 100 mK in either Cr‐ or V‐doped (Bi,Sb)2Te3 of the two experimentally confirmed QAH materials. Here it is shown that by codoping Cr and V magnetic elements in (Bi,Sb)2Te3 TI, the temperature of the QAH effect can be significantly increased such that full quantization is achieved at 300 mK, and zero‐field Hall resistance of 0.97 h/e2 is observed at 1.5 K. A systematic transport study of the codoped (Bi,Sb)2Te3 films with varied Cr/V ratios reveals that magnetic codoping improves the homogeneity of ferromagnetism and modulates the surface band structure. This work demonstrates magnetic codoping to be an effective strategy for achieving high‐temperature QAH effect in TIs. |
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| Keywords: | ferromagnetic homogeneity magnetic codoping quantum anomalous Hall effect topological insulators |
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