Magnetic polarons in a nonequilibrium polariton condensate

TL;DR

This paper explores how nonequilibrium conditions affect magnetic self-trapping in exciton-polariton condensates within magnetic semiconductors, revealing multiple polarons and a new critical self-trapping condition.

Contribution

It introduces a nonequilibrium analysis of magnetic polarons, deriving a new critical condition for self-trapping and analyzing the excitation spectrum.

Findings

Multiple polarons can coexist in the system.

A new critical condition for self-trapping is established.

Effective magnetic attraction mediates polariton interactions.

Abstract

We consider a condensate of exciton-polaritons in a diluted magnetic semiconductor microcavity. Such system may exhibit magnetic self-trapping in the case of sufficiently strong coupling between polaritons and magnetic ions embedded in the semiconductor. We investigate the effect of the nonequilibrium nature of exciton-polaritons on the physics of the resulting self-trapped magnetic polarons. We find that multiple polarons can exist at the same time, and derive a critical condition for self-trapping which is different to the one predicted previously in the equilibrium case. Using the Bogoliubov-de Gennes approximation, we calculate the excitation spectrum and provide a physical explanation in terms of the effective magnetic attraction between polaritons, mediated by the ion subsystem.