Self-bound droplets in quasi-two-dimensional dipolar condensates

TL;DR

This paper investigates the ground-state properties of self-bound dipolar droplets in quasi-two-dimensional condensates, revealing two quantum phases and a double-dip structure in the size-atom number relationship, validated by Gaussian state theory.

Contribution

It introduces the concept of two quantum phases in dipolar droplets and demonstrates their impact on observable properties, advancing understanding of quantum phase behavior in such systems.

Findings

Existence of two quantum phases: squeezed vacuum and squeezed coherent states.

Double-dip structure in the size versus atom number curve.

Quantum phases determine the critical atom number for self-bound droplets.

Abstract

We study the ground-state properties of self-bound dipolar droplets in quasi-two-dimensional geometry by using the Gaussian state theory. We show that there exist two quantum phases corresponding to the macroscopic squeezed vacuum and squeezed coherent states. We further show that the radial size versus atom number curve exhibits a double-dip structure, as a result of the multiple quantum phases. In particular, we find that the critical atom number for the self-bound droplets is determined by the quantum phases, which allows us to distinguish the quantum state and validates the Gaussian state theory.