2014/12/31 by É. V. Gorbar, E. V. Gorbar, V. A. Miransky +2 · 1 citation
Materials Science · Physics and Astronomy · #Computer science #Graphene research and applications #Physics #Quantum Mechanics and Non-Hermitian Physics #Topological Materials and Phenomena #cond-mat.str-el #hep-th #nucl-th
paper · pdf · doi:10.1103/physrevb.91.121101
published as Phys. Rev. B 91, 121101 (2015) · 6 pages, 2 figures; published version with minor changes and an extended discussion
openalex publication_date 2015/03/02 · arxiv created 2015/03/03 · arxiv updated 2015/03/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We demonstrate that the physical reason for the nontrivial topological properties of Dirac semimetals A3Bi (A=Na,K,Rb) is connected with a discrete symmetry of the low-energy effective Hamiltonian. By making use of this discrete symmetry, we argue that all electron states can be split into two separate sectors of the theory. Each sector describes a Weyl semimetal with a pair of Weyl nodes and broken time-reversal symmetry. The latter symmetry is not broken in the complete theory because the time-reversal transformation interchanges states from different sectors. Our findings are supported by explicit calculations of the Berry curvature. In each sector, the field lines of the curvature reveal a pair of monopoles of the Berry flux at the positions of Weyl nodes. The ℤ2 Weyl semimetal nature is also confirmed by the existence of pairs of surface Fermi arcs, which originate from different sectors of the theory.