Topological Phase Transitions in the Repulsively Interacting Haldane-Hubbard Model.
Using dynamical mean-field theory and exact diagonalization we study the phase diagram of the repulsive Haldane-Hubbard model, varying the interaction strength and the sublattice potential difference. In addition to the quantum Hall phase with Chern number C=2 and the band insulator with C=0 present already in the noninteracting model, the system also exhibits a C=0 Mott insulating phase, and a C=1 quantum Hall phase. We explain the latter phase by a spontaneous symmetry breaking where one of the spin components is in the Hall state and the other in the band insulating state.
COMP Centre of Excellence, Department of Applied Physics, Aalto University, Helsinki, Finland.|Theoretische Physik, ETH Zurich, 8093 Zurich, Switzerland.
Tuomas I
TI
Vanhala
COMP Centre of Excellence, Department of Applied Physics, Aalto University, Helsinki, Finland.
Topi
T
Siro
COMP Centre of Excellence, Department of Applied Physics, Aalto University, Helsinki, Finland.
Long
L
Liang
Theoretische Physik, ETH Zurich, 8093 Zurich, Switzerland.
Matthias
M
Troyer
COMP Centre of Excellence, Department of Applied Physics, Aalto University, Helsinki, Finland.
Ari
A
Harju
COMP Centre of Excellence, Department of Applied Physics, Aalto University, Helsinki, Finland.|Institute for Quantum Electronics, ETH Zurich, 8093 Zurich, Switzerland.
Päivi
P
Törmä