New classes of topological crystalline insulators having surface rotation anomaly
Name
eaat2374.full.pdf
Description
Published version
Size
418.58 KB
Format
Adobe PDF
Checksum (MD5)
bbe0a7115d3f98496b6fd7933d52669d
Author(s)
Fang, Chen
Fu, Liang
Date Issued
December 2019
Journal
Science Advances
Publisher
American Association for the Advancement of Science (AAAS)
Citation
Fang, Chen and Liang Fu. "New classes of topological crystalline insulators having surface rotation anomaly." Science Advances 5, 12 (December 2019): eaat2374 © 2019 The Authors
Version
Final published version
Abstract
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[subscript n]). The new anomalous states have n flavors of massless Dirac fermions protected by T and C[subscript 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[superscript 2]/h.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution NonCommercial License 4.0
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1126/sciadv.aat2374
