COLLOQUIUM 2013

- Campus Jussieu

Le colloquium Pierre et Marie Curie présente des exposés consacrés à la physique contemporaine et aux disciplines connexes. Ces exposés sont destinés à tous les étudiants et à tous les enseignants et chercheurs mais plus particulièrement aux étudiants de master et aux étudiants en thèse. Les exposés ont lieu soit en français soit en anglais.

Time reversal symmetry in optics


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Résumé

The presentation will start with an introduction to the general recipe for achieving optimum coupling of light to resonant optical material systems, such as Fabry Perot resonators, super- and sub-wavelength antenna structures. The extreme case for the latter is a single atom, which will be treated in detail. This coupling between light and a single atom is probably the most fundamental process in quantum optics. The best strategy for efficiently coupling light to a single atom in free space depends on the goal. If the goal is to maximally attenuate a laser beam, narrow-band on-resonance laser radiation is required as well as a wave front approaching the atom from a 2π solid angle. If, on the other hand, the goal is to fully absorb the light bringing the atom to the excited state with unit success probability one will have to provide a single photon designed to represent the time reversed wave packet which the atom would emit in a spontaneous emission process. Among other conditions this requires the single photon wave packet impinging from the full 4π solid angle and having the correct temporal shape. Any deviation from the perfect shape will reduce the efficiency. The state of the art is reviewed and the experimental progress is discussed. If the interaction is strong enough it will allow for building a few photon quantum gate without a cavity, with possible applications in quantum information processing such as a quantum repeater.


Orateur(s) : Gerd Leuchs, Directeur du Max Planck Institute for the Science of Light. Professeur aux département de Physique de l’Université Erlangen-Nuremberg (Allemagne) et de l’Université d’Ottawa (Canada)
Public : Tous
Date : 3 décembre 2013
Lieu : Campus Jussieu