Widely tunable Berry curvature in the magnetic semimetal Cr₁₊δTe₂

Magnetic semimetals have increasingly emerged as lucrative platforms hosting spin-based topological phenomena in real and momentum spaces. Cr1+δTe2 is a self-intercalated magnetic transition metal dichalcogenide (TMD), which exhibits topological magnetism and tunable electron filling. While recent s...

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Main Authors: Fujisawa, Yuita, Pardo-Almanza, Markel, Hsu, Chia-Hsiu, Mohamed, Atwa, Yamagami, Kohei, Krishnadas, Anjana, Chang, Guoqing, Chuang, Feng-Chuan, Khoo, Khoong Hong, Zang, Jiadong, Soumyanarayanan, Anjan, Okada, Yoshinori
Other Authors: School of Physical and Mathematical Sciences
Format: Article
Language:English
Published: 2023
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Online Access:https://hdl.handle.net/10356/164952
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spelling sg-ntu-dr.10356-1649522023-04-04T00:58:41Z Widely tunable Berry curvature in the magnetic semimetal Cr₁₊δTe₂ Fujisawa, Yuita Pardo-Almanza, Markel Hsu, Chia-Hsiu Mohamed, Atwa Yamagami, Kohei Krishnadas, Anjana Chang, Guoqing Chuang, Feng-Chuan Khoo, Khoong Hong Zang, Jiadong Soumyanarayanan, Anjan Okada, Yoshinori School of Physical and Mathematical Sciences Science::Physics::Electricity and magnetism Engineering::Materials::Magnetic materials Anomalous Hall Effects Berry Curvature Magnetic semimetals have increasingly emerged as lucrative platforms hosting spin-based topological phenomena in real and momentum spaces. Cr1+δTe2 is a self-intercalated magnetic transition metal dichalcogenide (TMD), which exhibits topological magnetism and tunable electron filling. While recent studies have explored real-space Berry curvature effects, similar considerations of momentum-space Berry curvature are lacking. Here, the electronic structure and transport properties of epitaxial Cr1+δTe2 thin films are systematically investigated over a range of doping, δ (0.33 – 0.71). Spectroscopic experiments reveal the presence of a characteristic semi-metallic band region, which shows a rigid like energy shift with δ. Transport experiments show that the intrinsic component of the anomalous Hall effect (AHE) is sizable and undergoes a sign flip across δ. Finally, density functional theory calculations establish a link between the doping evolution of the band structure and AHE: the AHE sign flip is shown to emerge from the sign change of the Berry curvature, as the semi-metallic band region crosses the Fermi energy. These findings underscore the increasing relevance of momentumspace Berry curvature in magnetic TMDs and provide a unique platform for intertwining topological physics in real and momentum spaces. Nanyang Technological University National Research Foundation (NRF) Published version Y.O. acknowledges support from CREST under Grants No. JPMJCR1812. A.S. and K.H.K. acknowledge the support of the SpOT-LITE program (Grant No. A18A6b0057), funded by Singapore's RIE2020 initiatives. F.C.C. and C.H.H. acknowledge support from the National Center for Theoretical Sciences and the Ministry of Science and Technology of Taiwan under Grants No. MOST-110-2112-M-110-013-MY3. F.C.C. and C.H.H. also acknowledge the National Center for High-performance Computing for computer time and facilities. G.C. was supported by the National Research Foundation, Singapore, under its NRF Fellowship Award (NRF-NRFF13 2021-0010) and the Nanyang Assistant Professorship grant from Nanyang Technological University. J.Z. was supported by the Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, U.S. Department of Energy, under Award No. DE-SC0020221. We are grateful for the help and support provided by the Engineering Support Section of Research Support Division at OIST. Most of the studies are supported by funding from the Quantum Material Science Unit-Okinawa Institute of Science and Technology Graduate University. 2023-03-06T01:20:24Z 2023-03-06T01:20:24Z 2023 Journal Article Fujisawa, Y., Pardo-Almanza, M., Hsu, C., Mohamed, A., Yamagami, K., Krishnadas, A., Chang, G., Chuang, F., Khoo, K. H., Zang, J., Soumyanarayanan, A. & Okada, Y. (2023). Widely tunable Berry curvature in the magnetic semimetal Cr₁₊δTe₂. Advanced Materials, 202207121-1-202207121-11. https://dx.doi.org/https://doi.org/10.1002/adma.202207121 0935-9648 https://hdl.handle.net/10356/164952 10.1002/adma.202207121 202207121-1 202207121-11 en NRF-NRFF13 2021-0010 Nanyang Assistant Professorship (NAP) Advanced Materials © 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Science::Physics::Electricity and magnetism
Engineering::Materials::Magnetic materials
Anomalous Hall Effects
Berry Curvature
spellingShingle Science::Physics::Electricity and magnetism
Engineering::Materials::Magnetic materials
Anomalous Hall Effects
Berry Curvature
Fujisawa, Yuita
Pardo-Almanza, Markel
Hsu, Chia-Hsiu
Mohamed, Atwa
Yamagami, Kohei
Krishnadas, Anjana
Chang, Guoqing
Chuang, Feng-Chuan
Khoo, Khoong Hong
Zang, Jiadong
Soumyanarayanan, Anjan
Okada, Yoshinori
Widely tunable Berry curvature in the magnetic semimetal Cr₁₊δTe₂
description Magnetic semimetals have increasingly emerged as lucrative platforms hosting spin-based topological phenomena in real and momentum spaces. Cr1+δTe2 is a self-intercalated magnetic transition metal dichalcogenide (TMD), which exhibits topological magnetism and tunable electron filling. While recent studies have explored real-space Berry curvature effects, similar considerations of momentum-space Berry curvature are lacking. Here, the electronic structure and transport properties of epitaxial Cr1+δTe2 thin films are systematically investigated over a range of doping, δ (0.33 – 0.71). Spectroscopic experiments reveal the presence of a characteristic semi-metallic band region, which shows a rigid like energy shift with δ. Transport experiments show that the intrinsic component of the anomalous Hall effect (AHE) is sizable and undergoes a sign flip across δ. Finally, density functional theory calculations establish a link between the doping evolution of the band structure and AHE: the AHE sign flip is shown to emerge from the sign change of the Berry curvature, as the semi-metallic band region crosses the Fermi energy. These findings underscore the increasing relevance of momentumspace Berry curvature in magnetic TMDs and provide a unique platform for intertwining topological physics in real and momentum spaces.
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Fujisawa, Yuita
Pardo-Almanza, Markel
Hsu, Chia-Hsiu
Mohamed, Atwa
Yamagami, Kohei
Krishnadas, Anjana
Chang, Guoqing
Chuang, Feng-Chuan
Khoo, Khoong Hong
Zang, Jiadong
Soumyanarayanan, Anjan
Okada, Yoshinori
format Article
author Fujisawa, Yuita
Pardo-Almanza, Markel
Hsu, Chia-Hsiu
Mohamed, Atwa
Yamagami, Kohei
Krishnadas, Anjana
Chang, Guoqing
Chuang, Feng-Chuan
Khoo, Khoong Hong
Zang, Jiadong
Soumyanarayanan, Anjan
Okada, Yoshinori
author_sort Fujisawa, Yuita
title Widely tunable Berry curvature in the magnetic semimetal Cr₁₊δTe₂
title_short Widely tunable Berry curvature in the magnetic semimetal Cr₁₊δTe₂
title_full Widely tunable Berry curvature in the magnetic semimetal Cr₁₊δTe₂
title_fullStr Widely tunable Berry curvature in the magnetic semimetal Cr₁₊δTe₂
title_full_unstemmed Widely tunable Berry curvature in the magnetic semimetal Cr₁₊δTe₂
title_sort widely tunable berry curvature in the magnetic semimetal cr₁₊δte₂
publishDate 2023
url https://hdl.handle.net/10356/164952
_version_ 1764208104018280448