Pairing in Asymmetric Many-Fermion Systems: Functional Renormalisation   Group Approach
  Functional renormalisation group approach is applied to a imbalanced many- fermion system with a short-range attractive force. Composite boson field is introduced to describe the pairing between different flavour fermions. A set of approximate flow equations for the effective couplings is derived and solved. We identify the critical values of mass and particle number density mismatch when the system undergoes a phase transition to a normal state and determine the phase diagram both at unitary regime and nearby. 
Boris Krippa
cond-mat.quant-gas cond-mat.supr-con nucl-th