Theoretical studies of magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulators

Abstract Optical approaches are useful for studying the electronic and spin structure of materials. Here, based on the tight-binding model and linear response theory, we investigate the magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulators (SOTI) with extern...

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Main Authors: Wan-Qing Zhu, Wen-Yu Shan
Format: Article
Language:English
Published: Nature Portfolio 2023-08-01
Series:Scientific Reports
Online Access:https://doi.org/10.1038/s41598-023-39644-y
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author Wan-Qing Zhu
Wen-Yu Shan
author_facet Wan-Qing Zhu
Wen-Yu Shan
author_sort Wan-Qing Zhu
collection DOAJ
description Abstract Optical approaches are useful for studying the electronic and spin structure of materials. Here, based on the tight-binding model and linear response theory, we investigate the magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulators (SOTI) with external magnetization. We find that orbital-dependent Zeeman term induces band crossings for SOTI phase, which are absent for trivial phase. In the weak-magnetization regime, these crossings give rise to giant jumps (peaks) of Kerr and Faraday angles (ellipticity) for SOTI phase. In the strong-magnetization regime, we find that two nearly flat bands are formed at the high-symmetry point of Brillouin zone of SOTI phase. These flat bands give rise to two successive giant jumps (peaks) of Kerr and Faraday angles (ellipticity). These phenomena provide new possibilities to characterize and detect the two-dimensional SOTI phase.
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spelling doaj.art-0228144d3d1f45d59b992086a1dc64ca2023-11-26T13:19:35ZengNature PortfolioScientific Reports2045-23222023-08-0113111210.1038/s41598-023-39644-yTheoretical studies of magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulatorsWan-Qing Zhu0Wen-Yu Shan1Department of Physics, School of Physics and Materials Science, Guangzhou UniversityDepartment of Physics, School of Physics and Materials Science, Guangzhou UniversityAbstract Optical approaches are useful for studying the electronic and spin structure of materials. Here, based on the tight-binding model and linear response theory, we investigate the magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulators (SOTI) with external magnetization. We find that orbital-dependent Zeeman term induces band crossings for SOTI phase, which are absent for trivial phase. In the weak-magnetization regime, these crossings give rise to giant jumps (peaks) of Kerr and Faraday angles (ellipticity) for SOTI phase. In the strong-magnetization regime, we find that two nearly flat bands are formed at the high-symmetry point of Brillouin zone of SOTI phase. These flat bands give rise to two successive giant jumps (peaks) of Kerr and Faraday angles (ellipticity). These phenomena provide new possibilities to characterize and detect the two-dimensional SOTI phase.https://doi.org/10.1038/s41598-023-39644-y
spellingShingle Wan-Qing Zhu
Wen-Yu Shan
Theoretical studies of magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulators
Scientific Reports
title Theoretical studies of magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulators
title_full Theoretical studies of magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulators
title_fullStr Theoretical studies of magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulators
title_full_unstemmed Theoretical studies of magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulators
title_short Theoretical studies of magneto-optical Kerr and Faraday effects in two-dimensional second-order topological insulators
title_sort theoretical studies of magneto optical kerr and faraday effects in two dimensional second order topological insulators
url https://doi.org/10.1038/s41598-023-39644-y
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