Sarchi, D.Savona, V.2009-09-222009-09-222009-09-22200710.1103/PhysRevB.75.115326https://infoscience.epfl.ch/handle/20.500.14299/42807WOS:000245329600093We adopt a kinetic theory of polariton nonequilibrium Bose-Einstein condensation to describe the formation of off-diagonal long-range order. The theory accounts properly for the dominant role of quantum fluctuations in the condensate. In realistic situations with optical excitation at high energy, it predicts a significant depletion of the condensate caused by long-wavelength fluctuations. As a consequence, the one-body density matrix in space displays a partially suppressed long-range order and a pronounced dependence on the finite size of the system.Quantum Kinetic-TheoryExciton PolaritonsPhotoluminescenceCoherenceGasesGaptext::journal::journal article::research article