The p-wave polaron

TL;DR

This paper investigates the properties of a p-wave polaron in a Fermi sea near a p-wave Feshbach resonance, revealing unique spectral features and anisotropic dispersion influenced by magnetic dipolar interactions.

Contribution

It introduces the concept of a third polaron branch and anisotropic dispersion in the p-wave case, expanding understanding beyond the s-wave scenario.

Findings

Discovery of a third polaron branch in the excitation spectrum.

Observation of anisotropic impurity dispersion with tunable effective masses.

Identification of magnetic field effects on resonance splitting and anisotropy.

Abstract

We consider the properties of a single impurity immersed in a Fermi sea close to an interspecies p-wave Feshbach resonance. We calculate its dispersion and spectral response to a radiofrequency pulse. In the presence of a magnetic field, dipolar interactions split the resonance and lead to the appearance of two novel features with respect to the s-wave case: a third polaron branch in the excitation spectrum, in addition to the usual attractive and repulsive ones; and an anisotropic dispersion of the impurity characterized by different effective masses perpendicular and parallel to the magnetic field. The anisotropy can be tuned as a function of the field strength and the two effective masses may have opposite signs, or become smaller than the bare mass.