A weakly-interacting many-body system of Rydberg polaritons based on electromagnetically induced transparency

We proposed utilizing a medium with high optical depth (OD) and Rydberg state of low principal quantum number, $n$, to create weakly-interacting many-body system polaritons, based on the effect electromagnetically induced transparency (EIT). experimentally verified mean field approach observed phase shift attenuation by dipole-dipole interaction (DDI). The DDI-induced or can be viewed as consequence elastic inelastic collisions among polaritons. Using system, we further that larger DDI strength caused width momentum distribution polaritons at exit become notably smaller compared entrance. In this study, took $n =32$ atomic (or polariton) density 5$\times10^{10}$ 2$\times10^{9}$) cm$^{-3}$. observations demonstrate are sufficient drive thermalization process in system. combination $\mu$s-long time due high-OD EIT $\mu$m$^2$-size collision cross section suggests new feasible platform for Bose-Einstein condensation