Abstract
We report two theoretical discoveries for topological metals and semimetals. It is shown first that any dimensional Fermi surface is topologically equivalent to a Fermi point. Then the famous conventional no-go theorem, which was merely proven before for 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 no-go theorem: all Fermi points have the same topological charge or 0 for periodic systems. Moreover, we also establish all six topological types of models for realistic physical dimensions.
- Received 11 June 2015
DOI:https://doi.org/10.1103/PhysRevLett.116.016401
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