Polaronic effects of an impurity in a Fermi superfluid away from the BEC limit

Abstract

In this article we study the interaction between an impurity and the gas of Bogoliubov excitations of a Fermi superfluid by mapping it on the polaron problem for an impurity in a BEC. The description of the Fermi superfluid across the BEC-BCS crossover regime is based on a recently developed effective field theory presented in [Eur. Phys. J. B 88, 122 (2015)] and provides us with the interaction-dependent dispersion relations for the Bogoliubov excitations. The behavior of the polaronic coupling constant $\alpha$ and of the effective mass of the polaron is examined in a broad window of the BEC-BCS crossover.

9 pages, 3 figures