1207.4547 (Tsuneya Yoshida et al.)

Topological antiferromagnetic phase in a correlated
Bernevig-Hughes-Zhang model    [PDF]

Tsuneya Yoshida, Robert Peters, Satoshi Fujimoto, Norio Kawakami

Topological properties of antiferromagnetic phases are studied for a correlated topological band insulator by applying the dynamical mean field theory to an extended Bernevig-Hughes-Zhang model including the Hubbard interaction. The calculation of the magnetic moment and the spin Chern number confirms the existence of a non-trivial antiferromagnetic (AF) phase beyond the Hartree-Fock theory. In particular, we uncover the intriguing fact that the topologically non-trivial AF phase is essentially stabilized by correlation effects but not by the Hartree shifts alone. This counterintuitive effect is demonstrated, through a comparison with the Hartree-Fock results, and should apply for generic topological insulators with strong correlations.

View original: http://arxiv.org/abs/1207.4547