Stability and breakdown of Fermi polarons in a strongly interacting Fermi-Bose mixture

The authors experimentally prepare and investigate the properties of a strongly interacting imbalanced mixture of bosonic 41K impurities immersed in a Fermi sea of ultracold 6Li atoms. Two configurations have been explored: a thermal regime described by the Fermi polaron picture and a partially Bose-Einstein-condensed regime described by coexisting Fermi and Bose polarons.