Enormous Berry-Curvature-Based 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

doi:10.1021/acsnano.1c08663

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

ACS Nano. 2022 Feb 22;16(2):2369-2380. doi: 10.1021/acsnano.1c08663. Epub 2022 Jan 31.

Authors

Wei-Jhih Zou¹, Meng-Xin Guo¹, Jyun-Fong Wong¹, Zih-Ping Huang², Jui-Min Chia¹, Wei-Nien Chen¹, Sheng-Xin Wang¹, Keng-Yung Lin², Lawrence Boyu Young², Yen-Hsun Glen Lin², Mohammad Yahyavi³, Chien-Ting Wu⁴, Horng-Tay Jeng^{1

5

6}, Shang-Fan Lee⁵, Tay-Rong Chang^{3

6

7}, Minghwei Hong², Jueinai Kwo¹

Affiliations

¹ Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan.
² Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 10617, Taiwan.
³ Department of Physics, National Cheng Kung University, Tainan 701, Taiwan.
⁴ Materials Analysis Division, Taiwan Semiconductor Research Institute, National Applied Research Laboratories, Hsinchu 300091, Taiwan.
⁵ Institute of Physics, Academia Sinica, Taipei 11529, Taiwan.
⁶ Physics Division, National Center for Theoretical Sciences, National Taiwan University, Taipei 10617, Taiwan.
⁷ Center for Quantum Frontiers of Research and Technology (QFort), Tainan 701, Taiwan.

PMID: 35099945
DOI: 10.1021/acsnano.1c08663

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 (Bi_0.3Sb_0.7)₂Te₃ (BST) based heterostructures with a ferrimagnetic insulator europium iron garnet (EuIG) of perpendicular magnetic anisotropy. Here we demonstrate large anomalous Hall resistance (R_AHE) exceeding 8 Ω (ρ_AHE of 3.2 μΩ·cm) at 300 K and sustaining to 400 K in 35 BST/EuIG samples, surpassing the past record of 0.28 Ω (ρ_AHE of 0.14 μΩ·cm) at 300 K. The large R_AHE is 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-like (THE-like) feature coexisting with AHE is observed at the negative top-gate voltage up to 15 K. Interface tuning with theoretical calculations has realized topologically distinct phenomena in tailored magnetic TI-based heterostructures.

Keywords: Berry curvature; anomalous Hall effect; first-principles calculations; magnetic insulator; magnetic proximity effect; topological insulator.