title: PT-Symmetric Real Dirac Fermions and Semimetals.
abstract: Recently, Weyl fermions have attracted increasing interest in condensed matter physics due to their rich phenomenology originated from their nontrivial monopole charges. Here, we present a theory of real Dirac points that can be understood as real monopoles in momentum space, serving as a real generalization of Weyl fermions with the reality being endowed by the PT symmetry. The real counterparts of topological features of Weyl semimetals, such as Nielsen-Ninomiya no-go theorem, 2D subtopological insulators, and Fermi arcs, are studied in the PT symmetric Dirac semimetals and the underlying reality-dependent topological structures are discussed. In particular, we construct a minimal model of the real Dirac semimetals based on recently proposed cold atom experiments and quantum materials about PT symmetric Dirac nodal line semimetals.
authors.affiliation: Max-Planck-Institute for Solid State Research, D-70569 Stuttgart, Germany.|Department of Physics and Center of Theoretical and Computational Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors.forename: Y X
authors.initials: YX
authors.lastname: Zhao
authors.affiliation: Max-Planck-Institute for Solid State Research, D-70569 Stuttgart, Germany.
authors.forename: Y
authors.initials: Y
authors.lastname: Lu