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Two-Dimensional Large Gap Topological Insulators with Tunable Rashba Spin-Orbit Coupling in Group-IV films

The coexistence of nontrivial topology and giant Rashba splitting, however, has rare been observed in two-dimensional (2D) films, limiting severely its potential applications at room temperature. Here, we through first-principles calculations to propose a series of inversion-asymmetric group-IV film...

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Autores principales: Zhang, Shou-juan, Ji, Wei-xiao, Zhang, Chang-wen, Li, Ping, Wang, Pei-ji
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5377469/
https://www.ncbi.nlm.nih.gov/pubmed/28368035
http://dx.doi.org/10.1038/srep45923
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author Zhang, Shou-juan
Ji, Wei-xiao
Zhang, Chang-wen
Li, Ping
Wang, Pei-ji
author_facet Zhang, Shou-juan
Ji, Wei-xiao
Zhang, Chang-wen
Li, Ping
Wang, Pei-ji
author_sort Zhang, Shou-juan
collection PubMed
description The coexistence of nontrivial topology and giant Rashba splitting, however, has rare been observed in two-dimensional (2D) films, limiting severely its potential applications at room temperature. Here, we through first-principles calculations to propose a series of inversion-asymmetric group-IV films, ABZ(2) (A ≠ B = Si, Ge, Sn, Pb; Z = F, Cl, Br), whose stability are confirmed by phonon spectrum calculations. The analyses of electronic structures reveal that they are intrinsic 2D TIs with a bulk gap as large as 0.74 eV, except for GeSiF(2), SnSiCl(2), GeSiCl(2) and GeSiBr(2) monolayers which can transform from normal to topological phases under appropriate tensile strain of 4, 4, 5, and 4%, respectively. The nontrivial topology is identified by Z(2) topological invariant together with helical edge states, as well as the berry curvature of these systems. Another prominent intriguing feature is the giant Rashba spin splitting with a magnitude reaching 0.15 eV, the largest value reported in 2D films so far. The tunability of Rashba SOC and band topology can be realized through achievable compressive/tensile strains (−4 ~ 6%). Also, the BaTe semiconductor is an ideal substrate for growing ABZ(2) films without destroying their nontrivial topology.
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spelling pubmed-53774692017-04-10 Two-Dimensional Large Gap Topological Insulators with Tunable Rashba Spin-Orbit Coupling in Group-IV films Zhang, Shou-juan Ji, Wei-xiao Zhang, Chang-wen Li, Ping Wang, Pei-ji Sci Rep Article The coexistence of nontrivial topology and giant Rashba splitting, however, has rare been observed in two-dimensional (2D) films, limiting severely its potential applications at room temperature. Here, we through first-principles calculations to propose a series of inversion-asymmetric group-IV films, ABZ(2) (A ≠ B = Si, Ge, Sn, Pb; Z = F, Cl, Br), whose stability are confirmed by phonon spectrum calculations. The analyses of electronic structures reveal that they are intrinsic 2D TIs with a bulk gap as large as 0.74 eV, except for GeSiF(2), SnSiCl(2), GeSiCl(2) and GeSiBr(2) monolayers which can transform from normal to topological phases under appropriate tensile strain of 4, 4, 5, and 4%, respectively. The nontrivial topology is identified by Z(2) topological invariant together with helical edge states, as well as the berry curvature of these systems. Another prominent intriguing feature is the giant Rashba spin splitting with a magnitude reaching 0.15 eV, the largest value reported in 2D films so far. The tunability of Rashba SOC and band topology can be realized through achievable compressive/tensile strains (−4 ~ 6%). Also, the BaTe semiconductor is an ideal substrate for growing ABZ(2) films without destroying their nontrivial topology. Nature Publishing Group 2017-04-03 /pmc/articles/PMC5377469/ /pubmed/28368035 http://dx.doi.org/10.1038/srep45923 Text en Copyright © 2017, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Zhang, Shou-juan
Ji, Wei-xiao
Zhang, Chang-wen
Li, Ping
Wang, Pei-ji
Two-Dimensional Large Gap Topological Insulators with Tunable Rashba Spin-Orbit Coupling in Group-IV films
title Two-Dimensional Large Gap Topological Insulators with Tunable Rashba Spin-Orbit Coupling in Group-IV films
title_full Two-Dimensional Large Gap Topological Insulators with Tunable Rashba Spin-Orbit Coupling in Group-IV films
title_fullStr Two-Dimensional Large Gap Topological Insulators with Tunable Rashba Spin-Orbit Coupling in Group-IV films
title_full_unstemmed Two-Dimensional Large Gap Topological Insulators with Tunable Rashba Spin-Orbit Coupling in Group-IV films
title_short Two-Dimensional Large Gap Topological Insulators with Tunable Rashba Spin-Orbit Coupling in Group-IV films
title_sort two-dimensional large gap topological insulators with tunable rashba spin-orbit coupling in group-iv films
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5377469/
https://www.ncbi.nlm.nih.gov/pubmed/28368035
http://dx.doi.org/10.1038/srep45923
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