Gap solitons of a superfluid fermion gas in optical lattices

Abstract

Based on the hydrodynamic model, gap soliton of a superfluid fermion gas in optical lattices was discussed. By using the variational method, the condition for existing gap soliton is obtained. It is found that, when the system crosses from Bose-Eingtein condensation side to the BCS side, the condition for existing gap soliton and the structure of gap soliton are very different.