# Dilute dipolar quantum droplets beyond the extended Gross-Pitaevskii equation

## TL;DR

This paper investigates the limitations of the extended Gross-Pitaevskii equation in describing dipolar quantum droplets, highlighting the importance of quantum correlations and proposing the system as a testbed for advanced many-body theories.

## Contribution

It compares experimental data with both eGPE and quantum Monte-Carlo simulations, revealing discrepancies and emphasizing the role of correlations beyond mean-field approximations.

## Key findings

- Discrepancies between experimental results and eGPE predictions.
- Quantum Monte-Carlo simulations align better with experiments.
- Quantum correlations are significant in the behavior of quantum droplets.

## Abstract

Dipolar quantum droplets are exotic quantum objects that are self-bound due to the subtle balance of attraction, repulsion and quantum correlations. Here we present a systematic study of the critical atom number of these self-bound droplets, comparing the experimental results with extended mean-field Gross-Pitaevskii equation (eGPE) and quantum Monte-Carlo simulations of the dilute system. The respective theoretical predictions differ, questioning the validity of the current theoretical state-of-the-art description of quantum droplets within the eGPE framework and indicating that correlations in the system are significant. Furthermore, we show that our system can serve as a sensitive testing ground for many-body theories in the near future.