Robust Dual Topological Character with Spin-Valley Polarization in a Monolayer of the Dirac Semimetal Na${}_3$Bi

Chengwang Niu, Patrick M. Buhl, Gustav Bihlmayer +4

Topological materials with both insulating and semimetal phases can be protected by crystalline (e.g. mirror) symmetry. The insulating phase, called topological crystalline insulat…