Rudi Grimm

Title

Two, Three, Many: When Atoms Interact in the Ultracold

Abstract

Ultracold quantum gases offer unique experimental access to study intriguing phenomena in few- and many- body quantum physics. The formation of weakly bound molecules plays  a key role as an entrance door in to this field. I will briefly review the formation of ultra cold dimers in atomic quantum gases, including most recent developments. I will then focus on three-body physics with ultracold atoms, presenting the first observation of a three-body scattering resonance. This observation, made in ultracold cesium in the nanokelvin range, reveals the presence of a long-sought “Efimov” trimer state, more than 36 years after its theoretical prediction. The last part of my talk will concern the fascinating many-body physics of ultracold fermions in the “BEC-BCS crossover”.