Destroying the superfluid state of fermionic atoms by the magnetic field in Feshbach resonance experiments

Abstract

We show that the superfluid state (SF) of fermionic atoms exist only for the magnetic fields lesser than the critical magnetic field. This critical magnetic field is determined by the equality of the Zeeman energy splitting for atoms with different spin projections to the energy gap of fermionic atoms without a magnetic field. For magnetic fields usually using in Feshbach resonance experiments a SF state is lost because these fields are much more than the critical field. We show that the transition temperature $ T_c $ of the SF state decreases as the magnetic field increases.