EQuAL Seminar: Diego Barberena

"Driven Superradiance in an Optical Cavity"

The behaviour of atoms driven by a laser and interacting with light inside an optical cavity is a standard problem in quantum optics that leads to a variety of rich phenomena, including steady state phase transitions, abrupt changes in dynamical evolution, optical bistability, etc. This is a consequence of the competition between, primarily, the effects of laser excitation and photon leakage through the cavity mirrors, but spontaneous emission of light into free space and cavity-mediated exchange interactions between atoms can change, sometimes drastically, the properties of the steady state. In this talk I will describe ongoing efforts to study, theoretically and experimentally, the dynamical and steady state properties of such a system in a regime where free space emission is much slower than other timescales in the problem. In this situation, we can access a metastable state determined entirely by collective atomic physics and captured by a model of driven superradiance. I will characterize the steady state phase transition that arises in this regime, its relation to Dicke superradiance, and finalize by commenting on the effects introduced by quantum fluctuations.