Discrete relaxation of exciton-polaritons in an inhomogeneous potential

TL;DR

This paper investigates how wave function stiffness during energy relaxation in exciton-polaritons manifests in both condensed and uncondensed states within an inhomogeneous potential, revealing new insights into polariton dynamics.

Contribution

It demonstrates that wave function stiffness effects are observable in uncondensed exciton-polaritons, extending understanding beyond condensate states.

Findings

Wave function stiffness influences energy relaxation in exciton-polaritons.

Nearly equally spaced energy levels are observed in uncondensed polaritons.

Inhomogeneous potentials affect the energy distribution of polaritons.

Abstract

We present indications, that the wave function-stiffness condition during energy-relaxation as observed in single-phase state quantum systems manifests also in a single particle ensemble. This is demonstrated for exciton-polaritons in the strong coupling regime in a ZnO-based microcavity at T = 10 K for non-resonant excitation. It is well known that the pump-induced spatially inhomogeneous background potential leads to nearly equally spaced energy levels in the k-space distribution for propagating polariton Bose-Einstein condensates. Surprisingly this particular pattern is also observable for uncondensed exciton-polaritons.