Effective Field Theory for Strongly Interacting Photons

Venue: Department of Physics, Seminar Room Fisica Teorica - 2nd floor

At 11.00

Michael Gullans
JQI, NIST and Univ. Maryland, USA

Abstract:
A promising route to scaling up quantum information systems is to strongly couple light, or other propagating quantum fields, to localized electronic degrees of freedom in solids or trapped atoms. These systems can be studied theoretically in analogous fashion to semiclassical nonlinear optics, where the electronic degrees of freedom are integrated out to give rise to effective photon-photon interactions.
In this talk, I will describe an approach we recently developed, based on effective field theory (EFT), to describe interacting photons in cold gases of Rydberg atoms. In these systems, the photons become dressed with highly excited Rydberg states to form so-called "Rydberg polaritons".
Using EFT, I will describe non-perturbative effects in N-body scattering of Rydberg polaritons, including the formation of N-body bound states and N-body interactions between photons. This work suggests that strongly interacting photons can realize new universality classes for few-body quantum systems.

Scientific Coordinator
dott. Iacopo Carusotto