General Hubbard model for strongly interacting fermions in an optical lattice and its phase detection

FOCUS center and MCTP, Department of Physics, University of Michigan - Ann Arbor, MI 48109, USA

Received: 18 September 2007
Accepted: 6 November 2007

Abstract

Based on the consideration of the system symmetry and its Hilbert space, we show that strongly interacting fermions near a wide Feshbach resonance in an optical lattice or superlattice can be generically described by a lattice resonance Hamiltonian. The latter can be mapped to a general Hubbard model with particle-assisted tunnelling rates. We investigate the model under population imbalance and show that the attractive and the repulsive models have the same complexity in the phase diagram under the particle-hole mapping. Using this mapping, we propose an experimental method to detect possible exotic superfluid/magnetic phases for this system.