Superfluidity and critical velocities in nonequilibrium Bose-Einstein condensatesSuperfluidity and critical velocities in nonequilibrium Bose-Einstein condensates
Faculty of Sciences. Physics

Theory of quantum systems and complex systems

article

2010New York, N.Y., 2010

Physics

Physical review letters. - New York, N.Y.

105(2010):2, 4 p.

0031-9007

020602

E-only publicatie

English (eng)

We theoretically study the superfluidity properties of a nonequilibrium Bose-Einstein condensate of exciton polaritons in a semiconductor microcavity under incoherent pumping. The dynamics of the condensate is described at mean-field level in terms of a generalized Gross-Pitaevskii equation. The drag force on a small moving object and the onset of fringes in the density profile are shown to have a sharp threshold as a function of the velocity; a generalized Landau criterion is developed to explain this behavior in terms of the dispersion of elementary excitations. Metastability of supercurrents in multiply-connected geometries is shown to persist up to higher flow speeds.

https://repository.uantwerpen.be/docman/irua/4abd6c/90aa0f8f.pdf