2017/08/31 by Zhida Song, Zhong Fang, Chen Fang · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.119.246402
published as Phys. Rev. Lett. 119, 246402 (2017) · v5, accepted in prl, the explicit Z8 Fu-Kane-like formulas provided
arxiv created 2017/11/15 · arxiv updated 2017/12/19
We study fourfold rotation invariant gapped topological systems with time-reversal symmetry in two and three dimensions (d=2,3). We show that in both cases nontrivial topology is manifested by the presence of the (d-2)-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 explicit construction of microscopic models having robust (d-2)-dimensional edge states.