Spontaneous coherent phase transition of polaritons in CdTe microcavities.
We report on evidence for polariton condensation out of a reservoir of incoherent polaritons. Polariton population and first-order coherence are investigated by spectroscopic imaging of the far-field emission of a CdTe-based microcavity under nonresonant pumping. With increasing pumping power, stimulated emission with thresholdlike behavior and spectral narrowing is observed in the strong exciton-photon coupling regime. We show that it comes from a narrow ring in k space, exhibiting enhanced spatial and angular coherence at the stimulation onset.
Richard
Maxime
M
CEA-CNRS-UJF group Nanophysique et semiconducteurs, Laboratoire de Spectrométrie Physique (CNRS UMR5588), Université J. Fourier-Grenoble, BP87, 38402 St Martin d'Hères, France.
Kasprzak
Jacek
J
Romestain
Robert
R
André
Régis
R
Dang
Le Si
le S