Fermi polarons with the finite-range fermion-impurity interactions

TL;DR

This paper analyzes the effects of finite-range fermion-impurity interactions on Fermi polarons, extending beyond s-wave scattering to include higher angular momentum channels, with implications for atomic gases and trapped impurities.

Contribution

It introduces an exact solution for Fermi polarons considering finite-range interactions and higher angular momentum channels, advancing understanding beyond standard s-wave models.

Findings

Finite-range interactions significantly alter polaron energy.

Higher angular momentum channels impact impurity behavior.

Results are relevant for atomic mixtures and optical trapping.

Abstract

We study a problem of an infinitely heavy impurity introduced into a polarized Fermi gas, which can be solved exactly with the help of Fumi's theorem. We consider the regime of finite-range fermion-impurity interactions beyond the standard $s$-wave scattering regime and investigate how this affects the energy of the polaron. We show how one can account for the effective range effects as well as the contribution from higher angular momentum channels, which are important for the study of ionic and Rydberg polarons. Our findings have relevance for atomic gas mixtures with a large mass imbalance and for the impurities trapped inside the optical tweezers.