Trieste Quantum Seminars:

Collective light-matter effects at the edge of Dicke's regime

Dr. Giovanni Ferioli
University of Florence, Italy

Abstract: The realization of a light-matter interface based on collective effects is an important goal of modern quantum optics. In this talk, I will present a series of experiments in which we have probed the subradiant [1] and superradiant [2] properties of a micrometer-sized cloud of thermal Rb atoms loaded in an optical tweezer with a volume comparable to the atomic transition cube. I will also describe a recent experiment where we studied the onset of the superradiant phase transition for the first time in free space [3], paving the way for the realization of a new class of time crystals. Finally, I will also present some collective features that are detectable via photon-photon correlation function [4].

[1] Physical Review X 11 (2), 021031
[2] Physical Review Letters 127 (24), 243602
[3] Nature Physics, 19, 1345-1349 (2023)
[4] Physical Review Letters 134 (15), 153602 (2025)