Self-bound Bose-Fermi liquids in lower dimensions

TL;DR

This paper investigates the formation of self-bound Bose-Fermi liquid droplets in 1D and 2D ultracold atomic mixtures, highlighting the different roles of quantum fluctuations in each dimension and predicting equilibrium densities.

Contribution

It demonstrates that quantum fluctuations are essential for droplet formation in 2D but negligible in 1D, where mean-field interactions suffice, providing stability criteria and density predictions.

Findings

Droplets in 2D arise from quantum fluctuation corrections.

In 1D, mean-field interactions alone can form droplets.

Predicted equilibrium densities for self-bound systems.

Abstract

We study weakly interacting mixtures of ultracold atoms composed of bosonic and fermionic species in 2D and 1D. When interactions between particles are appropriately tuned, self-bound quantum liquids can be formed. We show that while formation of these droplets in 2D is due to the higher order correction terms contributing to the total energy and originating in quantum fluctuations, in 1D geometry the quantum fluctuations have a negligible role on formation of the self-bound systems. The leading mean-field interactions are then sufficient for droplet formation in 1D. We analyse stability conditions for 2D and 1D systems and predict values of equilibrium densities of droplets.