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

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.