Feshbach resonances in an optical lattice

Dennis Dickerscheid

ITP, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands

We present the theory for ultracold atomic gases in an optical lattice near a Feshbach resonance. In the single-mode approximation the theory describes atoms and molecules hopping through the lattice and experiencing an avoided crossing at every site. We determine the microscopic parameters of the generalized Hubbard model that describes this physics, using the experimentally known parameters of the Feshbach resonance in the absence of the optical lattice. As an application we also calculate the zero-temperature phase diagram of an atomic Bose gas in an optical lattice.