Filling constraints for spin-orbit coupled insulators in symmorphic and nonsymmorphic crystals.

ABSTRACT: We determine conditions on the filling of electrons in a crystalline lattice to obtain the equivalent of a band insulator--a gapped insulator with neither symmetry breaking nor fractionalized excitations. We allow for strong interactions, which precludes a free particle description. Previous approaches that extend the Lieb-Schultz-Mattis argument invoked spin conservation in an essential way and cannot be applied to the physically interesting case of spin-orbit coupled systems. Here we introduce two approaches: The first one is an entanglement-based scheme, and the second one studies the system on an appropriate flat "Bieberbach" manifold to obtain the filling conditions for all 230 space groups. These approaches assume only time reversal rather than spin rotation invariance. The results d

SUBMITTER: Watanabe H 

PROVIDER: S-EPMC4664378 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature