Zero sound in a single component fermion - Bose Einstein Condensate   mixture
  The resonant dynamics of mediated interactions supports zero-sound in a cold atom degenerate mixture of a single component fermion gas and a Bose-Einstein condensate (BEC). We characterize the onset of instability in the phase separation of an unstable mixture and we find a rich collective mode structure for stable mixtures with one undamped mode that exhibits an avoided crossing and a Landau-damped mode that terminates. 
D. H. Santamore, Sergio Gaudio, Eddy Timmermans