Unconventional Anomalous Hall Effect Driven by Self-Intercalation in Covalent 2D Magnet Cr2Te3

Keke He; Mengying Bian; Samuel D Seddon; Koushik Jagadish; Andrea Mucchietto; He Ren; Erik Kirstein; Reza Asadi; Jaeil Bai; Chao Yao; Sheng Pan; Jie-Xiang Yu; Peter Milde; Chang Huai; Haolei Hui; Jiadong Zang; Renat Sabirianov; Xuemei M Cheng; Guoxing Miao; Hui Xing; Yu-Tsun Shao; Scott A Crooker; Lukas Eng; Yanglong Hou; Jonathan P Bird; Hao Zeng

doi:10.1002/advs.202407625

Unconventional Anomalous Hall Effect Driven by Self-Intercalation in Covalent 2D Magnet Cr₂Te₃

Adv Sci (Weinh). 2024 Nov 25:e2407625. doi: 10.1002/advs.202407625. Online ahead of print.

Authors

Keke He^{1

2}, Mengying Bian^{1

3

4}, Samuel D Seddon⁵, Koushik Jagadish⁶, Andrea Mucchietto⁷, He Ren⁸, Erik Kirstein⁷, Reza Asadi⁸, Jaeil Bai⁹, Chao Yao¹⁰, Sheng Pan¹¹, Jie-Xiang Yu¹¹, Peter Milde⁵, Chang Huai¹, Haolei Hui¹, Jiadong Zang¹², Renat Sabirianov⁹, Xuemei M Cheng¹³, Guoxing Miao⁸, Hui Xing¹⁰, Yu-Tsun Shao⁶, Scott A Crooker⁷, Lukas Eng⁵, Yanglong Hou^{3

14}, Jonathan P Bird², Hao Zeng¹

Affiliations

¹ Department of Physics, University at Buffalo, The State University of New York, Buffalo, NY, 14226, USA.
² Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, NY, 14226, USA.
³ School of Materials Science and Engineering, Peking University, Beijing, 100871, China.
⁴ College of Materials Science and Engineering, Beijing University of Technology, Beijing, 100124, China.
⁵ Institute of Applied Physics, Technical University of Dresden, 01187, Dresden, Germany.
⁶ Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, 90089, USA.
⁷ National High Magnetic Field Laboratory, Los Alamos National Lab, Los Alamos, NM, 87545, USA.
⁸ Department of Electrical and Computer Engineering Institute for Quantum Computing, University of Waterloo, Ontario, N2L3G1, Canada.
⁹ Department of Physics, University of Nebraska-Omaha, Omaha, NE, 68182, USA.
¹⁰ Key Laboratory of Artificial Structures and Quantum Control, Shanghai Center for Complex Physics, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.
¹¹ School of Physical science and Technology, Soochow University, Suzhou, 215006, China.
¹² Department of Physics and Astronomy, University of New Hampshire, Durham, NH, 03824, USA.
¹³ Physics Department, Bryn Mawr College, Bryn Mawr, PA, 19010, USA.
¹⁴ School of Materials, Sun Yat-Sen University, Shenzhen, 518107, China.

PMID: 39587440
DOI: 10.1002/advs.202407625

Abstract

Covalent 2D magnets such as Cr₂Te₃, which feature self-intercalated magnetic cations located between monolayers of transition-metal dichalcogenide material, offer a unique platform for controlling magnetic order and spin texture, enabling new potential applications for spintronic devices. Here, it is demonstrated that the unconventional anomalous Hall effect (AHE) in Cr₂Te₃, characterized by additional humps and dips near the coercive field in AHE hysteresis, originates from an intrinsic mechanism dictated by the self-intercalation. This mechanism is distinctly different from previously proposed mechanisms such as topological Hall effect, or two-channel AHE arising from spatial inhomogeneities. Crucially, multiple Weyl-like nodes emerge in the electronic band structure due to strong spin-orbit coupling, whose positions relative to the Fermi level is sensitively modulated by the canting angles of the self-intercalated Cr cations. These nodes contribute strongly to the Berry curvature and AHE conductivity. This component competes with the contribution from bands that are less affected by the self-intercalation, resulting in a sign change in AHE with temperature and the emergence of additional humps and dips. The findings provide compelling evidence for the intrinsic origin of the unconventional AHE in Cr₂Te₃ and further establish self-intercalation as a control knob for engineering AHE in complex magnets.

Keywords: 2D magnets; Berry curvature; Cr2Te3; anomalous Hall effect; intercalation.

Abstract

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