Coherence properties of the microcavity polariton condensateD. M. Whittaker1 and P. R. Eastham2
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
received on 2 July 2009; accepted in final form by M. C. Payne on 2 July 2009; published July 2009
published online 21 July 2009
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, g(1), 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, g(2), so it can be directly determined experimentally. The model explains recent experimental measurements of a relatively fast Gaussian decay for g(1), but also predicts a regime, further above threshold, where the decay is much slower.
71.36.+c - Polaritons (including photon-phonon and photon-magnon interactions).
78.20.Bh - Theory, models, and numerical simulation.
42.50.Lc - Quantum fluctuations, quantum noise, and quantum jumps.
© EPLA 2009