Novel Z_{2} Topological Metals and Semimetals
Abstract
We report two theoretical discoveries for Z_{2} topological metals and semimetals. It is shown first that any dimensional Z_{2} Fermi surface is topologically equivalent to a Fermi point. Then the famous conventional nogo theorem, which was merely proven before for Z Fermi points in a periodic system without any discrete symmetry, is generalized so that the total topological charge is zero for all cases. Most remarkably, we find and prove an unconventional strong nogo theorem: all Z_{2} Fermi points have the same topological charge ν_{Z 2}=1 or 0 for periodic systems. Moreover, we also establish all six topological types of Z_{2} models for realistic physical dimensions.
 Publication:

Physical Review Letters
 Pub Date:
 January 2016
 DOI:
 10.1103/PhysRevLett.116.016401
 arXiv:
 arXiv:1505.05826
 Bibcode:
 2016PhRvL.116a6401Z
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics;
 Condensed Matter  Materials Science;
 Condensed Matter  Other Condensed Matter
 EPrint:
 4 pages with Supplemental Material, 6 figures. Accepted by PRL