Spontaneous and triggered vortices in polariton OPO superfluids

TL;DR

This paper investigates vortex formation in non-equilibrium polariton superfluids within the optical parametric oscillator regime, revealing spontaneous symmetry breaking and vortex stability influenced by system parameters.

Contribution

It introduces a theoretical framework for understanding spontaneous and triggered vortices in polariton OPO superfluids using a two-component Gross-Pitaevskii model.

Findings

Spontaneous vortex formation occurs above the OPO threshold without external rotation.

Stable and metastable vortices are distinguished by their persistence and triggerability.

A generalized healing length characterizes vortices, depending solely on OPO parameters.

Abstract

We study non-equilibrium polariton superfluids in the optical parametric oscillator (OPO) regime using a two-component Gross-Pitaevskii equation with pumping and decay. We identify a regime above OPO threshold, where the system undergoes spontaneous symmetry breaking and is unstable towards vortex formation without any driving rotation. Stable vortex solutions differ from metastable ones; the latter can persist in OPO superfluids but can only be triggered externally. Both spontaneous and triggered vortices are characterised by a generalised healing length, specified by the OPO parameters only.