Extension of the Generalized Hydrodynamics to the Dimensional Crossover Regime

In an effort to address integrability breaking in cold gas experiments, we extend the integrable hydrodynamics of the Lieb-Liniger model with two additional components representing the population of atoms in the first and second transverse excited states, thus enabling a description of quasi-1D condensates. Collisions between different components are accounted for through the inclusion of a Boltzmann-type collision integral in the hydrodynamic equation. Contrary to standard generalized hydrodynamics, our extended model captures thermalization of the condensate at a rate consistent with experimental observations from a quantum Newton's cradle setup.

Automated summary

In this study, integrability breaking in cold gas experiments is addressed by extending the integrable hydrodynamics of the Lieb-Liniger model with two additional components representing the population of atoms in excited states. The extended model accounts for collisions between different components, capturing the thermalization of the condensate at a rate consistent with experimental observations. This model is in contrast to standard generalized hydrodynamics and provides a more accurate description of the thermalization process in quasi-1D condensates.