Quantum Optics Seminar by Tom Bienaimé – Niels Bohr Institute - University of Copenhagen

Niels Bohr Institute > Calendar > 2012 > Quantum Optics Seminar...

Quantum Optics Seminar by Tom Bienaimé

Summary: The problem of collective spontaneous emission has recently received growing interest with the study of single photon superradiance from N two-level atoms prepared by the absorption of one photon. Considering the decay of atoms prepared in the "timed Dicke state", strong forward emission is expected for extended systems, with a cooperative decay rate proportional to N and inversely proportional to the square of the atomic cloud size.

I will revisit the phenomenon of radiation pressure in a regime where scattering is dominated by cooperative effects and present the experiment which lead to the first observation of this effect.

I will also present our plans for the future. We want study subradiant states, where the energy remains partially trapped in the atomic system. We are also developing an original technique for compressing the cloud which consists of a rotating blue dipole trap. This will allow us to study the interplay between disorder and cooperativity in the dense regime. By dense, we mean according to the Ioffe Regel criterion (distance between two atoms ~ wavelength) where Anderson localization is expected.