Volume 81, Number 2, January 2008
Article Number 20001
Number of page(s) 5
Section General
Published online 03 December 2007
EPL, 81 (2008) 20001
DOI: 10.1209/0295-5075/81/20001

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

L.-M. Duan

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

received 18 September 2007; accepted in final form 6 November 2007; published January 2008
published online 3 December 2007

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.

03.75.Ss - Degenerate Fermi gases.
05.30.Fk - Fermion systems and electron gas.
34.50.-s - Scattering of atoms and molecules.

© EPLA 2008