Beyond Lee-Huang-Yang description of self-bound Bose mixtures

TL;DR

This paper develops a beyond mean-field theoretical framework for self-bound ultradilute Bose mixtures, accurately predicting their properties and stability, and aligning well with quantum Monte Carlo results across different dimensions and conditions.

Contribution

It introduces a self-consistent method to incorporate beyond Lee-Huang-Yang corrections, improving the description of self-bound Bose mixtures and their finite-size and temperature effects.

Findings

Excellent agreement with quantum Monte Carlo for ground state energies.

Accurate predictions of equilibrium properties in 1D mixtures.

Insights into temperature effects on liquid phase stability.

Abstract

We investigate the properties of self-bound ultradilute Bose-Bose mixtures, beyond the Lee-Huang-Yang description. Our approach is based on the determination of the beyond mean-field corrections to the phonon modes of the mixture in a self-consistent way and calculation of the associated equation of state. The newly obtained ground state energies show excellent agreement with recent quantum Monte Carlo calculations, providing a simple and accurate description of the self-bound mixtures with contact type interaction. We further show numerical results for the equilibrium properties of the finite size droplet, by adjusting the Gross-Pitaevskii equation. Our analysis is extended to the one-dimensional mixtures where an excellent agreement with quantum Monte Carlo predictions is found for the equilibrium densities. Finally, we discuss the effects of temperature on the stability of the liquid phase.