skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Proximity enhanced quantum spin Hall state in graphene

Abstract

Graphene is the first model system of two-dimensional topological insulator (TI), also known as quantum spin Hall (QSH) insulator. The QSH effect in graphene, however, has eluded direct experimental detection because of its extremely small energy gap due to the weak spin–orbit coupling. Here we predict by ab initio calculations a giant (three orders of magnitude) proximity induced enhancement of the TI energy gap in the graphene layer that is sandwiched between thin slabs of Sb 2Te 3 (or MoTe 2). This gap (1.5 meV) is accessible by existing experimental techniques, and it can be further enhanced by tuning the interlayer distance via compression. We reveal by a tight-binding study that the QSH state in graphene is driven by the Kane–Mele interaction in competition with Kekulé deformation and symmetry breaking. As a result, the present work identifies a new family of graphene-based TIs with an observable and controllable bulk energy gap in the graphene layer, thus opening a new avenue for direct verification and exploration of the long-sought QSH effect in graphene.

Authors:
 [1];  [1];  [2];  [1];  [3];  [1];  [4]
  1. Univ. of Bremen, Bremen (Germany)
  2. Max Planck Inst. for Chemical Physics of Solids, Dresden (Germany); Max Planck Institute for Physics of Complex Systems, Dresden (Germany)
  3. Max Planck Inst. for Chemical Physics of Solids, Dresden (Germany)
  4. Univ. of Nevada, Las Vegas, NV (United States)
Publication Date:
Research Org.:
Univ. of Nevada, Las Vegas, NV (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1332441
Alternate Identifier(s):
OSTI ID: 1337524
Grant/Contract Number:  
NA0001982
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Carbon
Additional Journal Information:
Journal Volume: 87; Journal Issue: C; Journal ID: ISSN 0008-6223
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Kou, Liangzhi, Hu, Feiming, Yan, Binghai, Wehling, Tim, Felser, Claudia, Frauenheim, Thomas, and Chen, Changfeng. Proximity enhanced quantum spin Hall state in graphene. United States: N. p., 2015. Web. doi:10.1016/j.carbon.2015.02.057.
Kou, Liangzhi, Hu, Feiming, Yan, Binghai, Wehling, Tim, Felser, Claudia, Frauenheim, Thomas, & Chen, Changfeng. Proximity enhanced quantum spin Hall state in graphene. United States. doi:10.1016/j.carbon.2015.02.057.
Kou, Liangzhi, Hu, Feiming, Yan, Binghai, Wehling, Tim, Felser, Claudia, Frauenheim, Thomas, and Chen, Changfeng. Mon . "Proximity enhanced quantum spin Hall state in graphene". United States. doi:10.1016/j.carbon.2015.02.057. https://www.osti.gov/servlets/purl/1332441.
@article{osti_1332441,
title = {Proximity enhanced quantum spin Hall state in graphene},
author = {Kou, Liangzhi and Hu, Feiming and Yan, Binghai and Wehling, Tim and Felser, Claudia and Frauenheim, Thomas and Chen, Changfeng},
abstractNote = {Graphene is the first model system of two-dimensional topological insulator (TI), also known as quantum spin Hall (QSH) insulator. The QSH effect in graphene, however, has eluded direct experimental detection because of its extremely small energy gap due to the weak spin–orbit coupling. Here we predict by ab initio calculations a giant (three orders of magnitude) proximity induced enhancement of the TI energy gap in the graphene layer that is sandwiched between thin slabs of Sb2Te3 (or MoTe2). This gap (1.5 meV) is accessible by existing experimental techniques, and it can be further enhanced by tuning the interlayer distance via compression. We reveal by a tight-binding study that the QSH state in graphene is driven by the Kane–Mele interaction in competition with Kekulé deformation and symmetry breaking. As a result, the present work identifies a new family of graphene-based TIs with an observable and controllable bulk energy gap in the graphene layer, thus opening a new avenue for direct verification and exploration of the long-sought QSH effect in graphene.},
doi = {10.1016/j.carbon.2015.02.057},
journal = {Carbon},
number = C,
volume = 87,
place = {United States},
year = {Mon Feb 23 00:00:00 EST 2015},
month = {Mon Feb 23 00:00:00 EST 2015}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 16 works
Citation information provided by
Web of Science

Save / Share: