Spin dynamics of single neutral impurities in a Bose-Einstein condensate

In this work, I report on the spin dynamics of individual neutral Cesium atoms interacting with an ultracold bath of Rubidium. This hybrid system experimentally realizes the paradigmatic model system of a single impurity in a Bose-Einstein condensate (BEC) and facilitates precision studies of atom-light and atom-atom interaction with kHz energy resolution. The results establish neutral Cesium atoms in a Rubidium BEC as a novel experimental platform, with future perspectives for local BEC probing, quantum information storage and entanglement creation, as well as for the investigation of individual neutral-atom collisions, entering the field of ultracold chemistry.