Static and dynamic properties of self-bound droplets of light in hot vapors

The propagation of light in nonlinear media is well described by a two-dimensional nonlinear Schrodinger equation (NLSE) within the paraxial approximation, which is equivalent to the Gross-Pitaevskii equation, the mean-field description for the dynamics of Bose-Einstein condensates (BECs). Due to this similarity, many theoretical and experimental investigations of phenomena which have already been studied and realized in BECs have been recently analyzed in alternative experimental platforms such as hot atomic vapors. In this work we study the formation of droplets of light in these media, attempting to establish a mapping between the experimental parameters normally used in BEC experiments and those needed to observe the analogous phenomenon in hot atomic vapors. We obtain the energy functional for the susceptibility of the medium in the chi (3), chi (3) + chi (5), and saturating regimes for a two-level atomic configuration considering the focusing (attractive) regime. We apply a Gaussian variational approach and check its predictions through numerical simulations of the NLSE for each regime. Finally, we study the real-time dynamics of the system for both the chi (3) + chi (5) and saturating nonlinearities, focusing our attention on the behavior of the breathing mode and on the analysis of droplet formation for realistic experimental conditions.