Abstract:

A cavity-polariton, formed due to the strong coupling between exciton and cavity mode, is one of the most promising composite bosons for realizing macroscopic spontaneous coherence at high temperature. Up to date, most of the experimental observations of polariton condensation were carried out in two-dimensional (2D) planar microcavities in which light field was confined one dimensionally [1-5]. However, the role of dimensionality in coherent quantum degeneracy of composite bosonic system of exciton polariton remains mysterious. Here we show the experimental observation of the room temperature one-dimensional (1D) polariton condensate in a ZnO microwire. A massive occupation of the polariton ground state above a distinct pumping power threshold is clearly demonstrated by using the angular resolved spectroscopy under non-resonant excitation. The power threshold is one order of magnitude lower than that of Mott transition. A well-defined far field emission pattern from the polariton condensate mode is clearly observed, manifesting the coherence build-up in the condensed polariton system.

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