Nonlinear effects in spin relaxation of cavity polaritons

TL;DR

This paper develops a kinetic formalism for spin and energy relaxation of cavity polaritons, incorporating redistribution mechanisms and bosonic stimulation, and applies it to experimental polarization dynamics in polariton parametric amplification.

Contribution

The paper introduces a comprehensive kinetic theory for polariton spin relaxation that accounts for all redistribution mechanisms and validates it with experimental polarization measurements.

Findings

Anisotropy in polariton interactions causes cross-linear polarization buildup.

Long-living linear polarization observed at zero detuning.

Self-induced Larmor precession effects modeled under elliptical pumping.

Abstract

We present the general kinetic formalism for the description of spin and energy relaxation of the cavity polaritons in the framework of the Born-Markov approximation. All essential mechanisms of polaritons redistribution in reciprocal space together with final state bosonic stimulation are taken into account, from our point of view. The developed theory is applied to describe our experimental results on the polarization dynamics obtained in the polariton parametric amplifier geometry (pumping at so-called magic angle). We have experimentally confirmed that the anisotropy of the polariton-polariton interaction is responsible for the build up of the cross-linear polarisation of the signal. The long-living linear polarization is observed at zero detuning. Under elliptical pumping, we have directly measured in the time domain and modelled the effect of self-induced Larmor precession.