Ferdinand Brennecke

Title

Strong Matter-Light Coupling in the Ultracold

Abstract

Quantum gases provide the opportunity to establish a direct link between experiment and generic models which capture the underlying physics. Ultracold atoms interact in a highly controlled way with coherent light fields revealing various aspects of the interplay between matter and light. In this talk, I will discuss recent experiments with an atomic Bose-Einstein condensate which strongly interacts with the field inside an optical high-finesse resonator. The ultimate control over atomic motion offers direct access to the quantum regime of cavity optomechanics with a collective density oscillation acting as a mechanical element. In a different setting our system realizes the famous Dicke model which was predicted in 1973 to show a quantum phase transition from a normal to a super-radiant phase. I will present recent experimental observation of this intriguing transition by means of atomic self-organization in a crystalline structure which exhibits properties of a supersolid phase.