Probing interactions between a charged impurity and a cold atomic bath in the quantum regime

ended

Here, I propose new experiments to study the ion-atom interaction in the quantum regime with an Yb+ impurity immersed in a bath of fermionic lithium atoms. Hybrid ion-atom systems combine the well-controllable platforms of trapped ions and ultracold quantum gases and link them together by the intermediate-range ion-atom interaction. These new quantum systems offer intriguing prospects for buffer gas cooling, quantum simulation of condensed matter/many-body systems as well as for state-to-state quantum chemistry. Although ultracold atoms and ions have each been routinely studied in the quantum regime, experiments with ion-atom mixtures remained firmly confined to the classical collision regime until very recently. As a first, the Yb+ - Li mixture has been cooled to the regime where quantum effects dominate the ion-atom interactions. With this unique system, I aim to understand, characterize, and control the ion-atom interaction in the quantum regime trough experiments. A key question to answer is: Can we find magneto-molecular (Feshbach) resonances? These resonances play a pivotal role in ultracold quantum gases, where the allow for atom-atom interaction tuning. So far, they have not been observed between atoms and ions because the required ultracold temperatures were not yet achieved. With the Yb+ - Li system there is now a good prospect for observing them. Next, I will study the coherence of ion motion in a quantum bath of fermionic atoms by preparing particular (non-classical) states of ion motion and monitoring their dynamics using tools derived from trapped-ion quantum computing. Together with a detailed study of the quantum chemistry within the mixture, this research will allow me to assess the suitability of this new quantum system in emerging quantum technology. The Marie Curie action offers a great possibility to combine my expertise on ultracold atoms together with the expertise of the host group in ion-atom systems and enhance my competences along the way.