Neutral impurities in a Bose-Einstein condensate for simulation of the Fröhlich-polaron

Abstract

We present an experimental system to study the Bose polaron by immersion of single, well-controllable neutral Cs impurities into a Rb Bose-Einstein condensate (BEC). We show that, by proper optical traps, independent control over impurity and BEC allows for precision relative positioning of the two sub-systems as well as for dynamical studies and independent read-out. We furthermore estimate that measuring the polaron binding energy of Fröhlich-type Bose polarons in the low and intermediate coupling regime is feasible with our experimental constraints and limitations discussed, and we outline how a parameter regime can be reached to characterize differences between Fröhlich and Bose-polaron in the strong coupling regime.