Superfluidity and Critical Velocities in Nonequilibrium Bose-Einstein Condensates
Authors: Wouters M., Carusotto I.
Autors Affiliation: Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland;
INO-CNR BEC Center and Dipartimento di Fisica, Universita` di Trento, I-38123 Povo, Italy
Abstract: 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.
Journal/Review: PHYSICAL REVIEW LETTERS
Volume: 105 (2) Pages from: 020602 to: 020602
KeyWords: superfluidity properties; exciton-polaritons; non-equilibrium; BEC; DOI: 10.1103/PhysRevLett.105.020602Citations: 89data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-09-13References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here