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Spin splitting in 2D monochalcogenide semiconductors

We report ab initio calculations of the spin splitting of the uppermost valence band (UVB) and the lowermost conduction band (LCB) in bulk and atomically thin GaS, GaSe, GaTe, and InSe. These layered monochalcogenides appear in four major polytypes depending on the stacking order, except for the mon...

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Autores principales: Do, Dat T., Mahanti, Subhendra D., Lai, Chih Wei
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4657021/
https://www.ncbi.nlm.nih.gov/pubmed/26596907
http://dx.doi.org/10.1038/srep17044
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author Do, Dat T.
Mahanti, Subhendra D.
Lai, Chih Wei
author_facet Do, Dat T.
Mahanti, Subhendra D.
Lai, Chih Wei
author_sort Do, Dat T.
collection PubMed
description We report ab initio calculations of the spin splitting of the uppermost valence band (UVB) and the lowermost conduction band (LCB) in bulk and atomically thin GaS, GaSe, GaTe, and InSe. These layered monochalcogenides appear in four major polytypes depending on the stacking order, except for the monoclinic GaTe. Bulk and few-layer ε-and γ -type, and odd-number β-type GaS, GaSe, and InSe crystals are noncentrosymmetric. The spin splittings of the UVB and the LCB near the Γ-point in the Brillouin zone are finite, but still smaller than those in a zinc-blende semiconductor such as GaAs. On the other hand, the spin splitting is zero in centrosymmetric bulk and even-number few-layer β-type GaS, GaSe, and InSe, owing to the constraint of spatial inversion symmetry. By contrast, GaTe exhibits zero spin splitting because it is centrosymmetric down to a single layer. In these monochalcogenide semiconductors, the separation of the non-degenerate conduction and valence bands from adjacent bands results in the suppression of Elliot-Yafet spin relaxation mechanism. Therefore, the electron- and hole-spin relaxation times in these systems with zero or minimal spin splittings are expected to exceed those in GaAs when the D’yakonov-Perel’ spin relaxation mechanism is also suppressed.
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spelling pubmed-46570212015-11-30 Spin splitting in 2D monochalcogenide semiconductors Do, Dat T. Mahanti, Subhendra D. Lai, Chih Wei Sci Rep Article We report ab initio calculations of the spin splitting of the uppermost valence band (UVB) and the lowermost conduction band (LCB) in bulk and atomically thin GaS, GaSe, GaTe, and InSe. These layered monochalcogenides appear in four major polytypes depending on the stacking order, except for the monoclinic GaTe. Bulk and few-layer ε-and γ -type, and odd-number β-type GaS, GaSe, and InSe crystals are noncentrosymmetric. The spin splittings of the UVB and the LCB near the Γ-point in the Brillouin zone are finite, but still smaller than those in a zinc-blende semiconductor such as GaAs. On the other hand, the spin splitting is zero in centrosymmetric bulk and even-number few-layer β-type GaS, GaSe, and InSe, owing to the constraint of spatial inversion symmetry. By contrast, GaTe exhibits zero spin splitting because it is centrosymmetric down to a single layer. In these monochalcogenide semiconductors, the separation of the non-degenerate conduction and valence bands from adjacent bands results in the suppression of Elliot-Yafet spin relaxation mechanism. Therefore, the electron- and hole-spin relaxation times in these systems with zero or minimal spin splittings are expected to exceed those in GaAs when the D’yakonov-Perel’ spin relaxation mechanism is also suppressed. Nature Publishing Group 2015-11-24 /pmc/articles/PMC4657021/ /pubmed/26596907 http://dx.doi.org/10.1038/srep17044 Text en Copyright © 2015, Macmillan Publishers Limited 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
Do, Dat T.
Mahanti, Subhendra D.
Lai, Chih Wei
Spin splitting in 2D monochalcogenide semiconductors
title Spin splitting in 2D monochalcogenide semiconductors
title_full Spin splitting in 2D monochalcogenide semiconductors
title_fullStr Spin splitting in 2D monochalcogenide semiconductors
title_full_unstemmed Spin splitting in 2D monochalcogenide semiconductors
title_short Spin splitting in 2D monochalcogenide semiconductors
title_sort spin splitting in 2d monochalcogenide semiconductors
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4657021/
https://www.ncbi.nlm.nih.gov/pubmed/26596907
http://dx.doi.org/10.1038/srep17044
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