Quantum Monte Carlo-based density functional for one-dimensional Bose-Bose mixtures

TL;DR

This paper develops a density functional approach based on Quantum Monte Carlo data to model two-component Bose mixtures in 1D, enabling analysis of dynamical properties and novel phenomena like anomalous dark solitons.

Contribution

It introduces a QMC-based density functional for 1D Bose-Bose mixtures, extending beyond Lee-Huang-Yang corrections and enabling dynamical studies.

Findings

Benchmark against QMC data across interaction regimes

Analysis of monopole modes in Bose mixtures

Discovery of anomalous dark solitons

Abstract

We propose and benchmark a Gross-Pitaevskii-like equation for two-component Bose mixtures with competing interactions in 1D. Our approach follows the density-functional theory with the energy functional based on the exact Quantum Monte Carlo (QMC) simulations. Our model covers, but goes beyond, the popular approach with the Lee-Huang-Yang corrections. We first benchmark our approach against available QMC data in all interaction regimes and then study dynamical properties, inaccessible by ab initio many-body simulations. Our analysis includes a study of monopole modes and reveals the presence of anomalous dark solitons.