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arXiv · 1004.1403

Antiferromagnetic topological insulators

Roger S. K. Mong·Andrew M. Essin·Joel E. Moore
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Abstract

We consider antiferromagnets breaking both time-reversal (Theta) and a primitive lattice translational symmetry (T) of a crystal but preserving the combination S = Theta T. The S symmetry leads to a Z_2 topological classification of insulators, separating the ordinary insulator phase from the "antiferromagnetic topological insulator" (AFTI) 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 (sigma_{xy} = e^2 / 2h), which may aid experimental confirmation of theta = pi 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.

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Roger S. K. Mong, Andrew M. Essin, Joel E. Moore. 2010-06-19. Antiferromagnetic topological insulators. https://doi.org/10.1103/physrevb.81.245209

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