TY - JOUR
T1 - Coherence properties and luminescence spectra of condensed polaritons in CdTe microcavities
AU - Szymanska, M. H.
AU - Marchetti, F. M.
AU - Keeling, Jonathan Mark James
AU - Littlewood, P. B.
PY - 2007/12
Y1 - 2007/12
N2 - We analyse the spatial and temporal coherence properties of a two-dimensional and finite sized polariton condensate with parameters tailored to the recent experiments which have shown spontaneous and thermal equilibrium polariton condensation in a CdTe microcavity [J. Kasprzak, M. Richard, S. Kundermann, A. Baas, P. Jeambrun, J.M.J. Keeling, F.M. Marchetti, M.H. Szymanska, R. Andre, J.L. Staehli, et al., Nature 443 (7110) (2006) 409]. We obtain a theoretical estimate of the thermal length, the lengthscale over which full coherence effectively exists (and beyond which power-law decay of correlations in a two-dimensional condensate occurs), of the order of 5 mu m. In addition, the exponential decay of temporal coherence predicted for a finite size system is consistent with that found in the experiment. From our analysis of the luminescence spectra of the polariton condensate, taking into account pumping and decay, we obtain a dispersionless region at small momenta of the order of 4 degrees. In addition, we determine the polariton linewidth as a function of the pump power. Finally, we discuss how, by increasing the exciton-photon detuning, it is in principle possible to move the threshold for condensation from a region of the phase diagram where polaritons can be described as a weakly interacting Bose gas to a region where instead the composite nature of polaritons becomes important. (C) 2007 Elsevier Ltd. All rights reserved.
AB - We analyse the spatial and temporal coherence properties of a two-dimensional and finite sized polariton condensate with parameters tailored to the recent experiments which have shown spontaneous and thermal equilibrium polariton condensation in a CdTe microcavity [J. Kasprzak, M. Richard, S. Kundermann, A. Baas, P. Jeambrun, J.M.J. Keeling, F.M. Marchetti, M.H. Szymanska, R. Andre, J.L. Staehli, et al., Nature 443 (7110) (2006) 409]. We obtain a theoretical estimate of the thermal length, the lengthscale over which full coherence effectively exists (and beyond which power-law decay of correlations in a two-dimensional condensate occurs), of the order of 5 mu m. In addition, the exponential decay of temporal coherence predicted for a finite size system is consistent with that found in the experiment. From our analysis of the luminescence spectra of the polariton condensate, taking into account pumping and decay, we obtain a dispersionless region at small momenta of the order of 4 degrees. In addition, we determine the polariton linewidth as a function of the pump power. Finally, we discuss how, by increasing the exciton-photon detuning, it is in principle possible to move the threshold for condensation from a region of the phase diagram where polaritons can be described as a weakly interacting Bose gas to a region where instead the composite nature of polaritons becomes important. (C) 2007 Elsevier Ltd. All rights reserved.
KW - microcavity polaritons
KW - quantum coherence
KW - Bose-Einstein condensation
KW - non-equilibrium
KW - BOSE-EINSTEIN CONDENSATION
KW - LASER
UR - http://www.scopus.com/inward/record.url?scp=35548974248&partnerID=8YFLogxK
U2 - 10.1016/j.ssc.2007.07.045
DO - 10.1016/j.ssc.2007.07.045
M3 - Article
SN - 0038-1098
VL - 144
SP - 364
EP - 370
JO - Solid State Communications
JF - Solid State Communications
IS - 9
ER -