Abstract
We consider antiferromagnets breaking both time-reversal and a primitive-lattice translational symmetry of a crystal but preserving the combination . The symmetry leads to a topological classification of insulators, separating the ordinary insulator phase from the “antiferromagnetic topological insulator” phase. This state is similar to the “strong” topological insulator with time-reversal symmetry and shares with it such properties as a quantized magnetoelectric effect. However, for certain surfaces the surface states are intrinsically gapped with a half-quantum Hall effect , which may aid experimental confirmation of quantized magnetoelectric coupling. Step edges on such a surface support gapless, chiral quantum wires. In closing we discuss GdBiPt as a possible example of this topological class.
1 More- Received 13 April 2010
DOI:https://doi.org/10.1103/PhysRevB.81.245209
©2010 American Physical Society