Description

2009/07/01, Miguel A. Cazalilla, Centro de Fisica de Materiales

Place: Salón de Grados, FCT-ZTF
Time: 12h.
Title: Quantum Simulation of the Hubbard model with Ultracold Atoms: The Attractive Route
Abstract
We study the conditions under which the phases sought after for the repulsive Hubbard model, namely a Mott insulator in the paramagnetic, and anti-ferromagnet, and a putative d-wave superfluid can be deduced from observations in an optical lattice loaded with a spin polarized ultra-cold Fermi gas with attractive interactions. Such a system thus realizes the attractive Hubbard model with spin imbalance. We show that, in the attractive Hubbard model and related by a well-known canonical transformation, the Mott insulator and antiferromagnetic phase of the repulsive Hubbard model are in fact easier to observe as a paired and superfluid phase, respectively. The putative d-wave superfluid phase of the repulsive Hubbard model doped away from half-filling is related to a d-wave antiferromagnetic phase for the attractive Hubbard model. We discuss the advantages of this approach to 'quantum simulate' the Hubbard model in an optical lattice over the approach that attempts to directly simulate the doped Hubbard model in the repulsive regime. We also point out a number of technical difficulties of the proposed approach and, in some cases, suggest possible solutions.