Three-dimensional symmetry breaking topological matters

Abstract

We discuss topological electronic states described by the Dirac Hamiltonian plus an additional one in three-dimension. When the additional Hamiltonian is an element of an Abelian group, electronic states become topologically nontrivial even in the absence of fundamental symmetries such as the time-reversal and the particle-hole symmety. The symmetry-breaking topological states are charercterized by the Chern number defined in the two-dimensional partial Brillouin zone. The topological insulators under Zeeman field are an example of the symmetry-breaking topological matters. We show the transision from the topological insulating phase to the topological semimetal one under the strong Zeeman field.