Enormous Berry-Curvature-Driven Anomalous Hall Effect in Topological Insulator (Bi,Sb)2Te3 on Ferrimagnetic Europium Iron Garnet beyond 400 K

Wei-Jhih Zou; Meng-Xin Guo; Jyun-Fong Wong; Zih-Ping Huang; Jui-Min Chia; Wei-Nien Chen; Sheng-Xin Wang; Keng-Yung Lin; Lawrence Boyu Young; Yen-Hsun Glen Lin; Mohammad Yahyavi; Chien-Ting Wu; Horng-Tay Jeng; Shang-Fan Lee; Tay-Rong Chang; Minghwei Hong; Jueinai Kwo

arXiv · 2103.16487

Enormous Berry-Curvature-Driven Anomalous Hall Effect in Topological Insulator (Bi,Sb)2Te3 on Ferrimagnetic Europium Iron Garnet beyond 400 K

Wei-Jhih Zou·Meng-Xin Guo·Jyun-Fong Wong·Zih-Ping Huang·Jui-Min Chia·Wei-Nien Chen·Sheng-Xin Wang·Keng-Yung Lin·Lawrence Boyu Young·Yen-Hsun Glen Lin·Mohammad Yahyavi·Chien-Ting Wu·Horng-Tay Jeng·Shang-Fan Lee·Tay-Rong Chang·Minghwei Hong·Jueinai Kwo

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Abstract

To realize the quantum anomalous Hall effect (QAHE) at elevated temperatures, the approach of magnetic proximity effect (MPE) was adopted to break the time-reversal symmetry in the topological insulator (Bi0.3Sb0.7)2Te3 (BST) based heterostructures with a ferrimagnetic insulator europium iron garnet (EuIG) of perpendicular magnetic anisotropy. Here we demonstrate phenomenally large anomalous Hall resistance (RAHE) exceeding 8 {\Omega} (\r{ho}AHE of 3.2 {\mu}{\Omega}*cm) at 300 K and sustaining to 400 K in 35 BST/EuIG samples, surpassing the past record of 0.28 {\Omega} (\r{ho}AHE of 0.14 {\mu}{\Omega}*cm) at 300 K. The remarkably large RAHE as attributed to an atomically abrupt, Fe-rich interface between BST and EuIG. Importantly, the gate dependence of the AHE loops shows no sign change with varying chemical potential. This observation is supported by our first-principles calculations via applying a gradient Zeeman field plus a contact potential on BST. Our calculations further demonstrate that the AHE in this heterostructure is attributed to the intrinsic Berry curvature. Furthermore, for gate-biased 4 nm BST on EuIG, a pronounced topological Hall effect (THE) coexisting with AHE is observed at the negative top-gate voltage up to 15 K. Interface tuning with theoretical calculations has opened up new opportunities to realize topologically distinct phenomena in tailored magnetic TI-based heterostructures.

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Wei-Jhih Zou, Meng-Xin Guo, Jyun-Fong Wong, Zih-Ping Huang, Jui-Min Chia, Wei-Nien Chen, Sheng-Xin Wang, Keng-Yung Lin, Lawrence Boyu Young, Yen-Hsun Glen Lin, Mohammad Yahyavi, Chien-Ting Wu, Horng-Tay Jeng, Shang-Fan Lee, Tay-Rong Chang, Minghwei Hong, Jueinai Kwo. 2021-03-30. Enormous Berry-Curvature-Driven Anomalous Hall Effect in Topological Insulator (Bi,Sb)2Te3 on Ferrimagnetic Europium Iron Garnet beyond 400 K. https://arxiv.org/abs/2103.16487

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