Polariton-polariton scattering: Exact results through a novel approachM. Combescot1, M. A. Dupertuis1, 2 and O. Betbeder-Matibet1
1 Institut des NanoSciences de Paris (INSP), Université Pierre et Marie Curie-Paris 6, Université Denis Diderot-Paris 7, CNRS, UMR 7588 - Campus Boucicaut, 140 rue de Lourmel, 75015 Paris
2 Laboratoire d'Optoélectronique Quantique, Ecole Polytechnique Fédérale de Lausanne (EPFL) Station 3, CH-1015 Lausanne, Switzerland
received 13 February 2007; accepted in final form 15 May 2007; published July 2007
published online 5 June 2007
We present a fully microscopic approach to the transition rate of two exciton-photon polaritons. The non-trivial consequences of the polariton composite nature -here treated exactly through a development of our composite-exciton many-body theory- lead to results noticeably different from the ones of the conventional approaches in which polaritons are mapped into elementary bosons. Our work reveals an appealing fundamental scattering which corresponds to a photon-assisted exchange -in the absence of Coulomb process. This scattering being dominant when one of the scattered polaritons has a strong photon character, it should be directly accessible to experiment. In the case of microcavity polaritons, it produces a significant enhancement of the polariton transition rate when compared to the one coming from Coulomb interaction. This paper also contains the crucial tools to securely tackle the many-body physics of polaritons, in particular towards its possible BEC.
71.36.+c - Polaritons (including photon-phonon and photon-magnon interactions).
71.35.-y - Excitons and related phenomena.
71.35.Lk - Collective effects (Bose effects, phase space filling, and excitonic phase transitions).
© Europhysics Letters Association 2007