Universal properties of dipolar Bose polarons in two dimensions

TL;DR

This paper investigates the universal behavior of dipolar Bose polarons in two dimensions, revealing how their properties depend on polarization angle and interaction anisotropy using ab-initio Monte Carlo methods.

Contribution

It provides the first ab-initio analysis of dipolar Bose polarons in 2D, highlighting universal scaling laws and anisotropic effective mass behavior.

Findings

Polaron energy and residue follow universal scaling with polarization angle.

Effective mass exhibits anisotropy increasing with tilt angle.

Monte Carlo results validate and delineate the limits of perturbative approaches.

Abstract

We study the quasiparticle properties of a dipolar impurity immersed in a two-dimensional dipolar bath. We use the ab-initio Diffusion Monte Carlo technique to determine the polaron energy, effective mass and quasiparticle residue. We find that both the polaron energy and quasiparticle residue follow a universal behaviour with respect to the polarization angle when properly scaled in terms of the scattering length. This trend is maintained over a wide range of values of the gas parameter, even in the highly correlated regime. Instead, the effective mass shows growing anisotropy as the tilting angle is increased, which is induced, mainly, by the anisotropy of the impurity-boson dipole-dipole interaction. Surprisingly, the effective mass is larger in the direction of minimum inter-particle repulsion. Finally, we use our Monte Carlo results to check the accuracy of perturbative approaches and determine their range of validity in terms of the gas parameter.