Abstract
We study fourfold rotation-invariant gapped topological systems with time-reversal symmetry in two and three dimensions (, 3). We show that in both cases nontrivial topology is manifested by the presence of the ()-dimensional edge states, existing at a point in 2D or along a line in 3D. For fermion systems without interaction, the bulk topological invariants are given in terms of the Wannier centers of filled bands and can be readily calculated using a Fu-Kane-like formula when inversion symmetry is also present. The theory is extended to strongly interacting systems through the explicit construction of microscopic models having robust ()-dimensional edge states.
- Received 14 August 2017
DOI:https://doi.org/10.1103/PhysRevLett.119.246402
© 2017 American Physical Society
Physics Subject Headings (PhySH)
Viewpoint
Topological Insulators Turn a Corner
Published 11 December 2017
Theorists have discovered topological insulators that are insulating in their interior and on their surfaces but have conducting channels at corners or along edges.
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