Coherence properties of the microcavity polariton condensate

¹  Department of Physics and Astronomy, University of Sheffield - Sheffield S3 7RH, UK, EU
²  Department of Physics, Imperial College London - London SW7 2AZ, UK, EU

Corresponding author: p.eastham@imperial.ac.uk

Received: 2 July 2009
Accepted: 2 July 2009

Abstract

A theoretical model is presented which explains the dominant decoherence process in a microcavity polariton condensate. The mechanism which is invoked is the effect of self-phase modulation, whereby interactions transform polariton number fluctuations into random energy variations. The model shows that the phase coherence decay, , has a Kubo form, which can be Gaussian or exponential, depending on whether the number fluctuations are slow or fast. This fluctuation rate also determines the decay time of the intensity correlation function, , so it can be directly determined experimentally. The model explains recent experimental measurements of a relatively fast Gaussian decay for , but also predicts a regime, further above threshold, where the decay is much slower.