Bell correlations between momentum-entangled pairs of 4He* atoms

The data supporting the findings of this study, available at https://arxiv.org/abs/2502.12392, are provided here. The datasets correspond to the plots and figures presented in the paper and are named accordingly. In this study, we report the experimental observation of Bell correlations in motional states of momentum-entangled ultracold helium atoms. Momentum-entangled pairs are first generated via s-wave collisions. Using a Rarity-Tapster interferometer and a Bell-test framework, we observe atom-atom correlations required for violation of a Bell inequality. This result shows the potential of ultracold atoms for fundamental tests of quantum mechanics and opens new avenues to studying gravitational effects in quantum states.