Droplets of trapped quantum dipolar bosons

TL;DR

This paper investigates the formation of stable droplet crystals in trapped dipolar bosons using Monte Carlo simulations, revealing a narrow interaction window for stability without extra forces, aligning with recent experimental observations.

Contribution

It demonstrates that stable droplet configurations in dipolar bosons arise solely from two-body interactions, without additional stabilizing mechanisms, and provides a scaling model for density profiles.

Findings

Stable droplet crystals form within a narrow interaction parameter window.

The number of droplets correlates with the Hamiltonian parameters and scattering length.

Results qualitatively match experimental observations of quantum Rosensweig instability.

Abstract

Strongly interacting systems of dipolar bosons in three dimensions confined by harmonic traps are analyzed using the exact Path Integral Ground State Monte Carlo method. By adding a repulsive two-body potential, we find a narrow window of interaction parameters leading to stable ground- state configurations of droplets in a crystalline arrangement. We find that this effect is entirely due to the interaction present in the Hamiltonian without resorting to additional stabilizing mechanisms or specific three-body forces. We analyze the number of droplets formed in terms of the Hamiltonian parameters, relate them to the corresponding s-wave scattering length, and discuss a simple scaling model for the density profiles. Our results are in qualitative agreement with recent experiments showing a quantum Rosensweig instability in trapped Dy atoms.