TY - JOUR
T1 - Group 14 element-based non-centrosymmetric quantum spin Hall insulators with large bulk gap
AU - Ma, Yandong
AU - Kou, Liangzhi
AU - Du, Aijun
AU - Heine, Thomas
N1 - Publisher Copyright:
© 2015, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2015/10/1
Y1 - 2015/10/1
N2 - To date, a number of two-dimensional (2D) topological insulators (TIs) have been realized in Group 14 elemental honeycomb lattices, but all are inversionsymmetric. Here, based on first-principles calculations, we predict a new family of 2D inversion-asymmetric TIs with sizeable bulk gaps from 105 meV to 284 meV, in X2–GeSn (X = H, F, Cl, Br, I) monolayers, making them in principle suitable for room-temperature applications. The nontrivial topological characteristics of inverted band orders are identified in pristine X2–GeSn with X = (F, Cl, Br, I), whereas H2–GeSn undergoes a nontrivial band inversion at 8% lattice expansion. Topologically protected edge states are identified in X2–GeSn with X = (F, Cl, Br, I), as well as in strained H2–GeSn. More importantly, the edges of these systems, which exhibit single-Dirac-cone characteristics located exactly in the middle of their bulk band gaps, are ideal for dissipationless transport. Thus, Group 14 elemental honeycomb lattices provide a fascinating playground for the manipulation of quantum states. [Figure not available: see fulltext.]
AB - To date, a number of two-dimensional (2D) topological insulators (TIs) have been realized in Group 14 elemental honeycomb lattices, but all are inversionsymmetric. Here, based on first-principles calculations, we predict a new family of 2D inversion-asymmetric TIs with sizeable bulk gaps from 105 meV to 284 meV, in X2–GeSn (X = H, F, Cl, Br, I) monolayers, making them in principle suitable for room-temperature applications. The nontrivial topological characteristics of inverted band orders are identified in pristine X2–GeSn with X = (F, Cl, Br, I), whereas H2–GeSn undergoes a nontrivial band inversion at 8% lattice expansion. Topologically protected edge states are identified in X2–GeSn with X = (F, Cl, Br, I), as well as in strained H2–GeSn. More importantly, the edges of these systems, which exhibit single-Dirac-cone characteristics located exactly in the middle of their bulk band gaps, are ideal for dissipationless transport. Thus, Group 14 elemental honeycomb lattices provide a fascinating playground for the manipulation of quantum states. [Figure not available: see fulltext.]
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U2 - 10.1007/s12274-015-0842-7
DO - 10.1007/s12274-015-0842-7
M3 - Article
AN - SCOPUS:84943365543
VL - 8
SP - 3412
EP - 3420
JO - Nano Research
JF - Nano Research
SN - 1998-0124
IS - 10
ER -