A Weakly-Interacting Many-Body System of Rydberg Polaritons Based on Electromagnetically Induced Transparency

• Published in: arXiv.org 2021-05
• Main Authors: Kim, Bongjune, Ko-Tang, Chen, Shih-Si Hsiao, Sheng-Yang, Wang, Kai-Bo, Li, Ruseckas, Julius, Juzeliunas, Gediminas, Kirova, Teodora, Auzinsh, Marcis, Ying-Cheng, Chen, Yong-Fan, Chen, Yu, Ite A
• Format: Article
• Language: English
• Subjects: Attenuation; Dipole interactions; Elastic scattering; Entrances; Inelastic collisions; Optical thickness; Phase shift; Polaritons; Rydberg states; Thermalization (energy absorption)
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2006.13526

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