Phase diagram of microcavity polariton condensates with a harmonic potential trap

TL;DR

This paper theoretically investigates phase transitions in inhomogeneous exciton-polariton condensates within a harmonic trap, identifying stable and unstable modes, including vortex states, through complex Gross-Pitaevskii analysis.

Contribution

It introduces a detailed phase diagram of polariton condensates with a harmonic potential, revealing two distinct stable phases and their excitation properties.

Findings

Identification of bifurcation points between stable and unstable modes

Discovery of two stable phases: BKT and localized-BEC

Characterization of elementary excitations and vortex stability

Abstract

We theoretically explore the phase transition in inhomogeneous exciton-polariton condensates with variable pumping conditions. Through Bogoliubov excitations to the radial-symmetric solutions of complex Gross-Pitaevskii equation, we determine not only the bifurcation of stable and unstable modes by the sign of fluid compressibility but also two distinct stable modes which are characterized by the elementary excitations and the stability of singly quantized vortex. One state is the quasi-condensate BKT phase with Goldstone flat dispersion; the other state is the localized-BEC phase which exhibits linear-type dispersion and has an excitation energy gap at zero momentum.