Distinguishing Surface and Bulk Electromagnetism via Their Dynamics in an Intrinsic Magnetic Topological Insulator

Fuente: arXiv
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Autori principali: Nguyen, Khanh Duy, Lee, Woojoo, Dang, Jianchen, Wu, Tongyao, Berruto, Gabriele, Yan, Chenhui, Ip, Chi Ian Jess, Lin, Haoran, Gao, Qiang, Lee, Seng Huat, Yan, Binghai, Liu, Chaoxing, Mao, Zhiqiang, Zhang, Xiao-Xiao, Yang, Shuolong
Natura: Preprint
Pubblicazione: 2024
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author Nguyen, Khanh Duy
Lee, Woojoo
Dang, Jianchen
Wu, Tongyao
Berruto, Gabriele
Yan, Chenhui
Ip, Chi Ian Jess
Lin, Haoran
Gao, Qiang
Lee, Seng Huat
Yan, Binghai
Liu, Chaoxing
Mao, Zhiqiang
Zhang, Xiao-Xiao
Yang, Shuolong
author_facet Nguyen, Khanh Duy
Lee, Woojoo
Dang, Jianchen
Wu, Tongyao
Berruto, Gabriele
Yan, Chenhui
Ip, Chi Ian Jess
Lin, Haoran
Gao, Qiang
Lee, Seng Huat
Yan, Binghai
Liu, Chaoxing
Mao, Zhiqiang
Zhang, Xiao-Xiao
Yang, Shuolong
contents The indirect exchange interaction between local magnetic moments via surface electrons has been long predicted to bolster the surface ferromagnetism in magnetic topological insulators (MTIs), which facilitates the quantum anomalous Hall effect. This unconventional effect is critical to determining the operating temperatures of future topotronic devices. However, the experimental confirmation of this mechanism remains elusive, especially in intrinsic MTIs. Here we combine time-resolved photoemission spectroscopy with time-resolved magneto-optical Kerr effect measurements to elucidate the unique electromagnetism at the surface of an intrinsic MTI MnBi2Te4. Theoretical modeling based on 2D Ruderman-Kittel-Kasuya-Yosida interactions captures the initial quenching of a surface-rooted exchange gap within a factor of two but over-estimates the bulk demagnetization by one order of magnitude. This mechanism directly explains the sizable gap in the quasi-2D electronic state and the nonzero residual magnetization in even-layer MnBi2Te4. Furthermore, it leads to efficient light-induced demagnetization comparable to state-of-the-art magnetophotonic crystals, promising an effective manipulation of magnetism and topological orders for future topotronics.
format Preprint
id arxiv_https___arxiv_org_abs_2407_00281
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Distinguishing Surface and Bulk Electromagnetism via Their Dynamics in an Intrinsic Magnetic Topological Insulator
Nguyen, Khanh Duy
Lee, Woojoo
Dang, Jianchen
Wu, Tongyao
Berruto, Gabriele
Yan, Chenhui
Ip, Chi Ian Jess
Lin, Haoran
Gao, Qiang
Lee, Seng Huat
Yan, Binghai
Liu, Chaoxing
Mao, Zhiqiang
Zhang, Xiao-Xiao
Yang, Shuolong
Strongly Correlated Electrons
Mesoscale and Nanoscale Physics
The indirect exchange interaction between local magnetic moments via surface electrons has been long predicted to bolster the surface ferromagnetism in magnetic topological insulators (MTIs), which facilitates the quantum anomalous Hall effect. This unconventional effect is critical to determining the operating temperatures of future topotronic devices. However, the experimental confirmation of this mechanism remains elusive, especially in intrinsic MTIs. Here we combine time-resolved photoemission spectroscopy with time-resolved magneto-optical Kerr effect measurements to elucidate the unique electromagnetism at the surface of an intrinsic MTI MnBi2Te4. Theoretical modeling based on 2D Ruderman-Kittel-Kasuya-Yosida interactions captures the initial quenching of a surface-rooted exchange gap within a factor of two but over-estimates the bulk demagnetization by one order of magnitude. This mechanism directly explains the sizable gap in the quasi-2D electronic state and the nonzero residual magnetization in even-layer MnBi2Te4. Furthermore, it leads to efficient light-induced demagnetization comparable to state-of-the-art magnetophotonic crystals, promising an effective manipulation of magnetism and topological orders for future topotronics.
title Distinguishing Surface and Bulk Electromagnetism via Their Dynamics in an Intrinsic Magnetic Topological Insulator
topic Strongly Correlated Electrons
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2407.00281