Subject：Emerging photon interactions from highly excited Rydberg atoms
Speaker：Prof. Thomas Pohl
Emcee：Prof. Guoxiang Huang
Time：4:00pm, 23th Jan, 2018
Place：Science Building A814
Thomas Pohl is Niels Bohr Professor at Aarhus University where he leads a group working on theoretical atomic physics, quantum optics and quantum many-body physics. His work has helped establishing several important concepts in the field of Rydberg atom physics, such as the notion of phase transitions to crystalline states, semi-classical approaches to driven-dissipative non-equilibrium dynamics in Rydberg-ensembles or so called Rydberg dressing as recently demonstrated in experiments. Moreover, his group and collaborators have pioneered the theory of quantum nonlinear optics and emerging photon interactions in interacting Rydberg ensembles. Current research interests include the study of exotic many-body physics of different nonlinear quantum photonic systems and ensuing applications.
Abstract：
The combination of electromagnetically induced transparency (EIT) and strongly interacting Rydberg states in cold atomic gases has opened up new routes towards achieving few-photon optical nonlinearities. While EIT provides strong light-matter coupling under low-loss conditions, the strong interactions between Rydberg states can be used to generate nonlinearities that are strong enough to operate on the level of single photons.
Such synthetic interactions enable few-photon applications and exotic many-body physics, emerging from the interplay of coherent driving, quantum light propagation, strong atomic interactions and dissipative photon scattering. In this talk, I will discuss the basic concepts behind such settings, based on specific examples that afford a simple and intuitive understanding. The combination of theory and experiments enables in-depth studies of many-body decoherence processes that are found to present challenges but also new opportunities for generating and manipulating nonclassical states of light. Finally, I will introduce new concepts beyond traditional Rydberg-EIT approaches and discuss corresponding prospects for technological applications and the observation of highly correlated multi-photon dynamics with current experimental capabilities.
