Collisional dynamics of polaronic clouds immersed in a Fermi sea

TL;DR

This paper introduces a new experimental protocol and nonlinear hydrodynamic simulation to study the collisional dynamics and many-polaron effects in a cold atom Fermi gas system, revealing shock waves and collective behaviors.

Contribution

It presents a novel experimental setup and simulation approach to analyze many-polaron properties and collective effects in a mass-balanced fermionic mixture.

Findings

Shock waves reflect many-body polaron properties.

Dynamics governed by impurity Fermi pressure, polaron energy, and multi-polaron correlations.

Applicable to Bose polarons and mass-imbalanced mixtures.

Abstract

We propose a new 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 {\it 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 multi-polaron 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.