Collisional dynamics of polaronic clouds immersed in a Fermi sea

We propose a protocol to examine many-polaron properties in a cold atom experiment. Initially, polaronic clouds are prepared around the opposite edges of a majority gas cloud. After time evolution, the collision of two clouds exhibits various polaronic effects. To see how collective properties of many polarons with mediated interactions appear in the case in which the impurity and majority gases are composed of mass-balanced fermions with different spin components, we perform a nonlinear hydrodynamic simulation for collisional dynamics of two Fermi polaronic clouds. We found that the dynamics is governed by the impurity Fermi pressure, polaron energy, and multipolaron correlations. In particular, shock waves occur in such a way as to reflect the many-body properties of polarons through the first sound of minority clouds. Our idea is applicable to other systems such as Bose polarons as well as mass-imbalanced mixtures.