In an effort to address integrability-breaking in cold gas experiments, we extend the integrable hydrodynamics of the Lieb-Liniger model with a second component. The additional component represents the population of transverse excited atoms found in quasi-1D condensates. Collisions between different components are accounted for through the inclusion of a Boltzmann-type collision integral in the hydrodynamic equation. We compare predictions of our model to measurements from a quantum Newtons cradle setup at short short to intermediate time scales and observe good agreement.
F. Møller, C. Li, I. Mazets, H.-P. Stimming, T. Zhou, Z. Zhu, X. Chen, and J. Schmiedmayer,
Extension of the Generalized Hydrodynamics to Dimensional Crossover Regime,
Related to Project A03