Polarons in supersolids: path-integral treatment of an impurity in a one-dimensional dipolar supersolid

TL;DR

This paper investigates the behavior of an impurity in a one-dimensional dipolar supersolid, calculating its ground-state energy and polaron radius using a variational path integral approach, revealing localization phenomena and phase transition effects.

Contribution

It introduces a path-integral method to study polarons in dipolar supersolids, providing new insights into impurity behavior and phase transition effects.

Findings

Divergence at the superfluid-supersolid phase transition.

Polaron can become localized to a single droplet.

Accurate ground-state energy calculations for supersolid polarons.

Abstract

The supersolid phase of a dipolar Bose-Einstein condensate has an intriguing excitation spectrum displaying a band structure. Here, the dressing of an impurity in a one-dimensional dipolar supersolid with the excitations of the supersolid is studied. The ground-state energy of the supersolid polaron is calculated using a variational path integral approach, which obtained accurate results for other polaron systems within the Bogoliubov and Fr\"ohlich approximations. A divergence is observed at the superfluid-supersolid phase transition. The polaron radius is also computed, showing that as a function of impurity-atom interactions, the polaron can become localized to a single droplet, behaving like a small solid-state polaron.