Spontaneous non-ground state polariton condensation in pillar microcavities

TL;DR

This paper reports the observation of spontaneous non-ground state polariton condensation in GaAs pillar microcavities, highlighting mode switching driven by exciton-exciton and pair polariton scattering mechanisms.

Contribution

It introduces the first observation of non-ground state polariton condensation with a model explaining mode switching based on scattering mechanisms.

Findings

Observation of non-ground state polariton condensation

Identification of mode switching between non-ground and ground states

A kinematic model explains the scattering-driven mode switching

Abstract

We observe spontaneously driven non-ground state polariton condensation in GaAs pillar microcavities under non-resonant optical excitation. We identify a regime where the interplay of exciton-exciton and pair polariton scattering can lead to mode switching from non-ground state to ground state polariton condensation. A simple kinematic model satisfactorily describes the observed mode switching as each of the above scattering mechanisms becomes prevalent at different carrier densities.