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Main Authors: Zhang, Wenfeng, Jia, Peizhe, Lou, Wen-kai, Wang, Xinghao, Su, Shaokui, Chang, Kai, Du, Rui-Rui
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2511.02281
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author Zhang, Wenfeng
Jia, Peizhe
Lou, Wen-kai
Wang, Xinghao
Su, Shaokui
Chang, Kai
Du, Rui-Rui
author_facet Zhang, Wenfeng
Jia, Peizhe
Lou, Wen-kai
Wang, Xinghao
Su, Shaokui
Chang, Kai
Du, Rui-Rui
contents The hybridization gap in strained-layer InAs/InxGa1-xSb quantum spin Hall insulators (QSHIs) is significantly enhanced compared to binary InAs/GaSb QSHI structures, where the typical indium composition, x, ranges between 0.2 and 0.4. This enhancement prompts a critical question: to what extent can quantum wells (QWs) be strained while still preserving the fundamental QSHI phase? In this study, we demonstrate the controlled molecular beam epitaxial (MBE) growth of highly strained-layer QWs with an indium composition of x = 0.5. These structures possess a substantial compressive strain within the In0.5Ga0.5Sb QW. Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films, indicating coherent lattice structures and the absence of visible dislocations. Transport measurements further reveal that the QSHI phase in InAs/In0.5Ga0.5Sb QWs is robust and protected by time-reversal symmetry. Notably, the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field. This behavior is in agreement with the Z2 topological property predicted by the Bernevig-Hughes-Zhang (BHZ) model, confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.
format Preprint
id arxiv_https___arxiv_org_abs_2511_02281
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Hybridization Gap and Edge States in Strained-layer InAs/In0.5Ga0.5Sb Quantum Spin Hall Insulator
Zhang, Wenfeng
Jia, Peizhe
Lou, Wen-kai
Wang, Xinghao
Su, Shaokui
Chang, Kai
Du, Rui-Rui
Materials Science
The hybridization gap in strained-layer InAs/InxGa1-xSb quantum spin Hall insulators (QSHIs) is significantly enhanced compared to binary InAs/GaSb QSHI structures, where the typical indium composition, x, ranges between 0.2 and 0.4. This enhancement prompts a critical question: to what extent can quantum wells (QWs) be strained while still preserving the fundamental QSHI phase? In this study, we demonstrate the controlled molecular beam epitaxial (MBE) growth of highly strained-layer QWs with an indium composition of x = 0.5. These structures possess a substantial compressive strain within the In0.5Ga0.5Sb QW. Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films, indicating coherent lattice structures and the absence of visible dislocations. Transport measurements further reveal that the QSHI phase in InAs/In0.5Ga0.5Sb QWs is robust and protected by time-reversal symmetry. Notably, the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field. This behavior is in agreement with the Z2 topological property predicted by the Bernevig-Hughes-Zhang (BHZ) model, confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.
title Hybridization Gap and Edge States in Strained-layer InAs/In0.5Ga0.5Sb Quantum Spin Hall Insulator
topic Materials Science
url https://arxiv.org/abs/2511.02281