Seminar given by Jan Arlt (Univ. Aarhus)

Seminar given by Jan Arlt (Univ. Aarhus), Tuesday 27 February 2024 at 4:00pm in the Auditorium of the Institut d'Optique Graduate School in Palaiseau, on the topic: "Quantum beat spectroscopy of the repulsive Bose polaron."

Abstract: "The physics of strongly interacting quantum systems is a challenging many-body problem that remains to be understood in its full complexity. I will discuss the case of impurities with strong attractive or repulsive interactions in a quantum degenerate gas of 39K atoms. By using a Ramsey-type sequence we observe purely decaying or oscillatory signals consistent with quasiparticle states: the attractive and repulsive polarons. The interferometric signal allows us to extract polaron energies for a wide range of interaction strengths, complimenting earlier spectroscopic measurements. Furthermore, several dynamical regimes towards the formation of the Bose polaron are identified. These results improve the understanding of quantum impurities interacting strongly with a bosonic environment and demonstrate how many-body states can be probed using Ramsey interferometry."