paper

Long-range Coulomb Interaction effects on Topological Phase Transitions between Semi-metals and Insulators

arXiv:1802.05727 · doi:10.1103/PhysRevB.97.241101

Abstract

Topological states may be protected by a lattice symmetry in a class of topological semi-metals. In three spatial dimensions, the Berry flux around gapless excitations in momentum space defines a chirality concretely, so a protecting symmetry may be referred to as a chiral symmetry. Prime examples include Dirac semi-metal (DSM) in a distorted spinel, BiZnSiO, protected by a mirror symmetry and DSM in NaBi, protected by a rotational symmetry. In these states, topology and a chiral symmetry are intrinsically tied. In this work, we investigate characteristics interplay between a chiral symmetry order parameter and instantaneous long-range Coulomb interaction with the standard renormalization group method. We show that a topological transition associated with a chiral symmetry is stable under the presence of the Coulomb interaction and the electron velocity always becomes faster than one of a chiral symmetry order parameter. Thus, the transition {\it must not} be relativistic, which implies a supersymmetry is intrinsically forbidden by the long-range Coulomb interaction. {Asymptotically exact} universal ratios of physical quantities such as energy gap ratio are obtained, and connections with experiments and recent theoretical proposals are also discussed.

arXiv commentPublished at PRB Rapid Communication (Phys. Rev. B 97, 241101(R) (2018)), Main text: 6 pages, 1 table, 2 figures, Supplementary Meterial: 9 pages, 3 figures

References in corpus (45)

Cited by in corpus (10)