Emergence of topological semimetals in gap closing in semiconductors without inversion symmetry.

ABSTRACT: A band gap for electronic states in crystals governs various properties of solids, such as transport, optical, and magnetic properties. Its estimation and control have been an important issue in solid-state physics. The band gap can be controlled externally by various parameters, such as pressure, atomic compositions, and external field. Sometimes, the gap even collapses by tuning some parameter. In the field of topological insulators, this closing of the gap at a time-reversal invariant momentum indicates a band inversion, that is, it leads to a topological phase transition from a normal insulator to a topological insulator. We show, through an exhaustive study on possible space groups, that the gap closing in inversion-asymmetric crystals is universal, in the sense that the gap closing a

SUBMITTER: Murakami S 

PROVIDER: S-EPMC5429037 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature