Fermion pairing with population imbalance: energy landscape and phase   separation in a constrained Hilbert subspace
  In this Letter we map out the mean field energy potential landscape of fermion pairing states with population imbalance near broad Feshbach Resonances. We apply the landscape to investigate the nature of phase separation, when the Hilbert space is subject to the constraint of constant population imbalance. We calculate the scattering length dependence of the critical population imbalance for various phase separated states across Feshbach resonances. 
Zheng-Cheng Gu, Geoff Warner and Fei Zhou (UBC)