title: Stability criteria for breached-pair superfluidity.
abstract: We present simple, concrete, two-fermion models that exhibit thermodynamically stable isotropic translationally invariant gapless superfluid states (breached-pair superfluidity). The mass ratio between the components and the momentum structure of the interaction are crucial for determining the stability of such states: idealized, momentum-independent ("contact") interactions are insufficient.
authors.affiliation: Center for Theoretical Physics, Department of Physics, MIT, Cambridge, MA 02139, USA.
authors.forename: Michael McNeil
authors.initials: MM
authors.lastname: Forbes
authors.forename: Elena
authors.initials: E
authors.lastname: Gubankova
authors.forename: W Vincent
authors.initials: WV
authors.lastname: Liu
authors.forename: Frank
authors.initials: F
authors.lastname: Wilczek