Quantum filaments in dipolar Bose-Einstein condensates

TL;DR

This paper explains how quantum fluctuations stabilize dipolar Bose-Einstein condensates against collapse, leading to the formation of self-bound filament-like droplets, which align with recent experimental observations in dysprosium gases.

Contribution

It introduces a mechanism where quantum fluctuations counteract dipole-driven collapse, resulting in stable filament-like droplets in dipolar BECs, a novel insight into their stability.

Findings

Quantum fluctuations prevent collapse in dipolar BECs.

Formation of self-bound filament-like droplets observed.

Mechanism explains recent dysprosium experiment results.

Abstract

Collapse in dipolar Bose-Einstein condensates may be arrested by quantum fluctuations. Due to the anisotropy of the dipole-dipole interactions, the dipole-driven collapse induced by soft excitations is compensated by the repulsive Lee-Huang-Yang contribution resulting from quantum fluctuations of hard excitations, in a similar mechanism as that recently proposed for Bose-Bose mixtures. The arrested collapse results in self-bound filament-like droplets, providing an explanation to recent dysprosium experiments. Arrested instability and droplet formation are novel general features directly linked to the nature of the dipole-dipole interactions, and should hence play an important role in all future experiments with strongly dipolar gases.