Bose-Einstein Condensation of Microcavity Polaritons in a Trap

We have created polaritons in a harmonic potential trap analogous to atoms in optical traps. The trap can be loaded by creating polaritons 50 ìm from its center and letting them drift into the trap. When the density of polaritons exceeds a critical threshold, we observe a number of signatures of Bose- Einstein condensation: spectral and spatial narrowing, a peak at k = 0 in the momentum distribution, first-order coherence, and spontaneous linear polarization of the light emission. The polaritons, which are eigenstates of theWe have created polaritons in a harmonic potential trap analogous to atoms in optical traps. The trap can be loaded by creating polaritons 50 ìm from its center and letting them drift into the trap. When the density of polaritons exceeds a critical threshold, we observe a number of signatures of Bose- Einstein condensation: spectral and spatial narrowing, a peak at k = 0 in the momentum distribution, first-order coherence, and spontaneous linear polarization of the light emission. The polaritons, which are eigenstates of the light-matter system in a microcavity, remain in the strong coupling regime while going through this dynamical phase transition. light-matter system in a microcavity, remain in the strong coupling regime while going through this dynamical phase transition.