Two-dimensional vortex quantum droplets get thick

TL;DR

This study investigates stable two-dimensional vortex quantum droplets under thicker transverse confinement, revealing new stability conditions, interaction behaviors, and the ability to support higher topological charges compared to thin confinement systems.

Contribution

It introduces a new regime for 2D vortex quantum droplets with thicker confinement, reformulates their properties, and explores their stability, interactions, and complex nested structures.

Findings

Stable vortex QDs with topological charge up to 4.

Strong repulsion between QDs due to higher-order LHY term.

Elastic and inelastic collision dynamics studied.

Abstract

We study two-dimensional (2D) vortex quantum droplets (QDs) trapped by a thicker transverse confinement with a>1um. Under this circumstance, the Lee-Huang-Yang (LHY) term should be described by its original form in the three-dimensional (3D) configuration. Previous studies have demonstrated that stable 2D vortex QDs can be supported by a thin transverse confinement with a<<1um. In this case, the LHY term is described by a logarithm. Hence, two kinds of confinement features result in different mechanisms of the vortex QDs. The stabilities and characteristics of the vortex QDs must be re-identified. In the current system, we find that stable 2D vortex QDs can be supported with topological charge number up to at least 4. We reformulated their density profile, chemical potential and threshold norm for supporting the stable vortex QDs according to the new condition. Unlike the QDs under thin confinement, the QDs in the current system strongly repel each other because the LHY term features a higher-order repulsion than that of the thin confinement system. Moreover, elastic and inelastic collisions between two moving vortex QDs are studied throughout the paper. Two kinds of collisions can be characterized by exerting different values of related speed. The dynamics of the stable nested vortex QD, which is constructed by embedding one vortex QD with a smaller topological number into another vortex QD with a larger number of topological charge, can be supported by the system.