Microscopic derivation of Hubbard parameters for cold atomic gases.
We study the exact solution for two atomic particles in an optical lattice interacting via a Feshbach resonance. The analysis includes the influence of all higher bands, as well as the proper renormalization of molecular energy in the closed channel. This exact solution allows for the precise determination of the parameters in the Hubbard model and the two-particle bound state energy. We identify the regime, where a single band Hubbard model fails to describe the scattering properties of the atoms as well as the bound states energies.
Büchler
Hans Peter
HP
Institute for Theoretical Physics III, University of Stuttgart, Germany.