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New classes of topological crystalline insulators having surface rotation anomaly

We discover new types of quantum anomalies in two-dimensional systems with time-reversal symmetry (T) and discrete rotation symmetry with order of n = 2, 4, and 6 (C(n)). The new anomalous states have n flavors of massless Dirac fermions protected by T and C(n), whereas any two-dimensional lattices...

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Autores principales: Fang, Chen, Fu, Liang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6924984/
https://www.ncbi.nlm.nih.gov/pubmed/31903416
http://dx.doi.org/10.1126/sciadv.aat2374
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author Fang, Chen
Fu, Liang
author_facet Fang, Chen
Fu, Liang
author_sort Fang, Chen
collection PubMed
description We discover new types of quantum anomalies in two-dimensional systems with time-reversal symmetry (T) and discrete rotation symmetry with order of n = 2, 4, and 6 (C(n)). The new anomalous states have n flavors of massless Dirac fermions protected by T and C(n), whereas any two-dimensional lattices having the two symmetries must have a multiple of 4, 8, and 12 Dirac cones for n = 2, 4, and 6, respectively. We show that these anomalous states are physically realized on the surface of new classes of topological crystalline insulators, normal to the rotation axis. Moreover, these topological crystalline insulators support n gapless one-dimensional helical mode on the otherwise fully gapped side surface, connecting the anomalous two-dimensional states on the top and bottom surfaces. The presence of these helical modes enables a new quantum device made from a topological crystalline insulator nanorod, a “helical nanorod,” which has a quantized longitudinal conductance of ne(2)/h.
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spelling pubmed-69249842020-01-03 New classes of topological crystalline insulators having surface rotation anomaly Fang, Chen Fu, Liang Sci Adv Research Articles We discover new types of quantum anomalies in two-dimensional systems with time-reversal symmetry (T) and discrete rotation symmetry with order of n = 2, 4, and 6 (C(n)). The new anomalous states have n flavors of massless Dirac fermions protected by T and C(n), whereas any two-dimensional lattices having the two symmetries must have a multiple of 4, 8, and 12 Dirac cones for n = 2, 4, and 6, respectively. We show that these anomalous states are physically realized on the surface of new classes of topological crystalline insulators, normal to the rotation axis. Moreover, these topological crystalline insulators support n gapless one-dimensional helical mode on the otherwise fully gapped side surface, connecting the anomalous two-dimensional states on the top and bottom surfaces. The presence of these helical modes enables a new quantum device made from a topological crystalline insulator nanorod, a “helical nanorod,” which has a quantized longitudinal conductance of ne(2)/h. American Association for the Advancement of Science 2019-12-20 /pmc/articles/PMC6924984/ /pubmed/31903416 http://dx.doi.org/10.1126/sciadv.aat2374 Text en Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). http://creativecommons.org/licenses/by-nc/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license (http://creativecommons.org/licenses/by-nc/4.0/) , which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.
spellingShingle Research Articles
Fang, Chen
Fu, Liang
New classes of topological crystalline insulators having surface rotation anomaly
title New classes of topological crystalline insulators having surface rotation anomaly
title_full New classes of topological crystalline insulators having surface rotation anomaly
title_fullStr New classes of topological crystalline insulators having surface rotation anomaly
title_full_unstemmed New classes of topological crystalline insulators having surface rotation anomaly
title_short New classes of topological crystalline insulators having surface rotation anomaly
title_sort new classes of topological crystalline insulators having surface rotation anomaly
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6924984/
https://www.ncbi.nlm.nih.gov/pubmed/31903416
http://dx.doi.org/10.1126/sciadv.aat2374
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