Are non-equilibrium Bose-Einstein condensates superfluid?

TL;DR

This paper investigates whether non-equilibrium Bose-Einstein condensates of exciton-polaritons exhibit superfluidity by analyzing their dynamics and stability using a modified Complex Ginzburg Landau equation and a generalized Landau criterion.

Contribution

It introduces a theoretical framework for understanding superfluidity in non-equilibrium condensates and extends the Landau criterion to these systems.

Findings

Superfluid behavior persists in non-equilibrium condensates under certain conditions.

Metastable supercurrents can exist at higher flow speeds.

A generalized Landau criterion estimates the onset of drag force in these systems.

Abstract

We theoretically study the superfluidity properties of a non-equilibrium Bose-Einstein condensate of exciton-polaritons in a semiconductor microcavity. The dynamics of the condensate is described at mean-field level in terms of a modified Complex Ginzburg Landau equation. A generalized Landau criterion is formulated which estimates the onset of the drag force on a small moving defect. Metastability of supercurrents in multiply connected geometries persists up to higher flow speeds.