Spatial Coherence Properties of One-Dimensional   Exciton-Polariton-Condensates
  In this work, we combine a systematic experimental investigation of the power- and temperaturedependent evolution of the spatial coherence function, g(1) (r), in a one-dimensional excitonpolariton channel with a modern microscopic numerical theory based on a stochastic master equation approach. The spatial coherence function g(1) (r) is extracted via high-precision Michelson interferometry, which allows us to demonstrate that in the regime of non-resonant excitation, the dependence g(1) (r) reaches a saturation value with a plateau, determined by the intensity of pump and effective temperature of the crystal lattice. The theory, which was extended to allow for treating incoherent excitation in a stochastic frame, matches the experimental data with good qualitative and quantitative agreement. This allows us to verify the prediction that the decay of the off-diagonal long range order can be almost fully suppressed in one-dimensional condensate systems. 
J. Fischer, I. G. Savenko, M.D. Fraser, S. Holzinger, S. Brodbeck, M.   Kamp, I. A. Shelykh, C. Schneider, and S. H\"ofling
cond-mat.mes-hall