Abstract
I calculate the superfluid density of a nonequilibrium steady state condensate of particles with finite lifetime. Despite the absence of a simple Landau critical velocity, a superfluid response survives, but dissipation reduces the superfluid fraction. I also suggest an idea for how the superfluid density of an example of such a system, i.e., microcavity polaritons, might be measured.
- Received 10 June 2011
DOI:https://doi.org/10.1103/PhysRevLett.107.080402
© 2011 American Physical Society