# Observation of Quantum Droplets in a Heteronuclear Bosonic Mixture

## TL;DR

This paper reports the experimental observation of long-lived quantum droplets formed in a heteronuclear mixture of 41K and 87Rb, demonstrating their stability and dynamics under various conditions, and confirming theoretical predictions.

## Contribution

First experimental observation of heteronuclear quantum droplets in a bosonic mixture, validating beyond mean-field theory across different interaction regimes.

## Key findings

- Long-lived self-bound states observed in free space and waveguide.
- Transition from expanding to localized states with interaction tuning.
- Good agreement between experimental results and theoretical models.

## Abstract

We report on the formation of heteronuclear quantum droplets in an attractive bosonic mixture of 41K and 87Rb. We observe long-lived self-bound states, both in free space and in an optical waveguide. In the latter case, the dynamics under the effect of a species-dependent force confirms their bound nature. By tuning the interactions from the weakly to the strongly attractive regime, we study the transition from expanding to localized states, in both geometries. We compare the experimental results with beyond mean-field theory and we find a good agreement in the full range of explored interactions. Our findings open up the production of long-lived droplets with important implications for further research.