1. Refractive index of a dilute Bose gas
- Author
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Yvan Castin, Jean Dalibard, Olivier Morice, Laboratoire Kastler Brossel (LKB (Lhomond)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectroscopie Hertzienne de l'ENS (LSH-ENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Charles Fabry de l'Institut d'Optique (LCFIO), and Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Condensed Matter::Quantum Gases ,Physics ,Photon ,Condensed matter physics ,Bose gas ,Scattering ,Sous embargo ,Order (ring theory) ,DALIBARD Jean ,Autre lien d'accès au document ,Correlation function (quantum field theory) ,Omega ,Atomic and Molecular Physics, and Optics ,symbols.namesake ,[PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph] ,Dispersion relation ,symbols ,van der Waals force ,Document sous DOI (Digital Object Identifier) ,web-atomes-rayonnement - Abstract
We derive the dispersion relation for the propagation of quasiresonant light with frequency ${\mathrm{\ensuremath{\omega}}}_{\mathit{L}}$ in an ultracold gas of bosonic atoms in the dilute regime, i.e., for an atomic density ${\mathrm{\ensuremath{\rho}}}_{0}$\ensuremath{\ll}(${\mathrm{\ensuremath{\omega}}}_{\mathit{L}}$/c${)}^{3}$. In our calculation, valid up to order 2 in density, two types of corrections to the Lorentz-Lorenz formula for the refractive index appear. The first one is due to the bosonic nature of the atoms and its contribution is related to the two-body correlation function. The second correction originates from multiple scattering of photons within pairs of close atoms, giving rise to the resonant van der Waals interaction. The temperature dependence of the refractive index gives a clear signature of quantum statistical effects, even if the degeneracy threshold for Bose-Einstein condensation is not reached.
- Published
- 1995
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