Abstract
Gapless surface states of time reversal invariant topological insulators are protected by the antiunitary nature of the time-reversal operation. Very recently, this idea was generalized to magnetic structures, in which time-reversal symmetry is explicitly broken, but there is still an antiunitary symmetry operation combining time-reversal symmetry and crystalline symmetry. These topological phases in magnetic structures are dubbed “topological magnetic crystalline insulators.” In this work, we present a general theory of topological magnetic crystalline insulators in different types of magnetic crystals based on the corepresentation theory of magnetic crystalline symmetry groups. We construct two concrete tight-binding models of topological magnetic crystalline insulators, the model and the model, in which topological surface states and topological invariants are calculated explicitly. Moreover, we check different types of antiunitary operators in magnetic systems and find that the systems with , and symmetry are able to protect gapless surface states. Our work will pave the way to search for topological magnetic crystalline insulators in realistic magnetic materials.
- Received 22 February 2014
- Revised 1 March 2015
DOI:https://doi.org/10.1103/PhysRevB.91.115317
©2015 American Physical Society