%0 Journal Article
%T Impact of biexcitons on the relaxation mechanisms of polaritons in III-nitride based multi-quantum well microcavities.
%+ Cavendish Laboratory
%+ Institute of Condensed Matter Physics [Lausanne]
%+ Laboratoire Charles Coulomb (L2C)
%A Corfdir, P.
%A Levrat, J.
%A Rossbach, G.
%A Butté, R.
%A Feltin, E.
%A Carlin, J.F.
%A Christmann, G.
%A Lefebvre, Pierre
%A Ganière, Jean-Daniel
%A Grandjean, N.
%A Deveaud-Plédran, Benoit
%Z NCCRQuantum Photonics-Swiss National Science Foundation (Grant No. 129715 and Grant No. 200020-113542).
%< avec comité de lecture
%@ 1098-0121
%J Physical Review B: Condensed Matter and Materials Physics (1998-2015)
%I American Physical Society
%V 85
%N 24
%P 245308
%8 2012-06-13
%D 2012
%R 10.1103/PhysRevB.85.245308
%Z PACS: 78.67.De ; 78.47.jd
%Z Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]Journal articles
%X We report on the direct observation of biexcitons in a III-nitride based multiple quantum well microcavity operating in the strong light-matter coupling regime by means of nonresonant continuous wave and time-resolved photoluminescence at low temperature. First, the biexciton dynamics is investigated for the bare active medium (multiple quantum wells alone) evidencing localization on potential fluctuations due to alloy disorder and thermalization between both localized and free excitonic and biexcitonic populations. Then, the role of biexcitons is considered for the full microcavity: in particular, we observe that for specific detunings the bottom of the lower polariton branch is directly fed by the radiative dissociation of either cavity biexcitons or excitons mediated by one LO-phonon. Accordingly, minimum polariton lasing thresholds are observed, when the bottom of the lower polariton branch corresponds in energy to the exciton or cavity biexciton first LO-phonon replica. This singular observation highlights the role of excitonic molecules in the polariton condensate formation process as being a more efficient relaxation channel when compared to the usually assumed acoustical phonon emission one.
%G English
%2 https://hal.science/hal-00708277/document
%2 https://hal.science/hal-00708277/file/PhysRevB.85.245308-Pierre-Corfdir.pdf
%L hal-00708277
%U https://hal.science/hal-00708277
%~ CNRS
%~ OPENAIRE
%~ L2C
%~ UNIV-MONTPELLIER
%~ UM-2015-2021
%~ UM-EPE