Physics & Astronomy Colloquium – Spring 2019 – Fleischauer

Speaker: Michael Fleischhauer (Univ. of Kaiserslautern)

Title: Non-local nonlinear optics using Rydberg atoms

Abstract: Photons do not easily interact with each other and nonlinear processes
on the few-photon level can usually be realized only under very special
conditions. Coupling of weak light fields to atoms involving Rydberg states
may change this picture. Under conditions of electromagnetically induced
transparency (EIT) such a coupling leads to the formation of Rydberg polaritons
which are quasi-particles with tunable composition and effective mass, and strong, non-local interactions. The latter can turn photons into hard-sphere objects with a finite avoided volume in two particle correlations or lead to bound states of photon pairs, i.e.
photonic molecules. I will explain the physics of Rydberg polaritons, review
the experimental status and discuss interesting many-body effects arizing from
the long-range interaction such as the formation of crystals of single-photon wavelets and unconventional fractional quantum Hall states.