Z(2) Topological insulator of ultracold atoms in bichromatic optical lattices

Abstract

We investigate the effect of a strong bichromatic deformation to the Z(2), topological insulator in a fermionic ultracold atomic system proposed by Beri and Cooper [Phys. Rev. Lett. 107 (2011) 145301]. Large insulating gap of this system allows for examination of strong perturbations. We conclude that the Z(2) topological character of the system is robust against a large global perturbation which breaks the inversion symmetry but preserves the time-reversal symmetry.