Rapidity and momentum distributions of 1D dipolar quantum gases

We explore the effect of tunable integrability breaking dipole-dipole interactions in the equilibrium states of highly magnetic 1D Bose gases of dysprosium at low temperatures, using measurements of rapidity and momentum distributions. In the strongly correlated Tonks-Girardeau regime, those distributions are nearly unaffected by the dipolar interactions. This suggests that bare quasiparticles can be used to characterize that regime. By contrast, decreasing the strength of the contact interactions results in higher 1D densities and stronger dipolar interactions, which produce significant changes of the rapidity and momentum distributions. This indicates that the dressing of the quasiparticles needs to be accounted for to characterize that regime. We show that modeling the system as an array of 1D gases with only contact interactions, dressed with the contribution of the short-range part of the dipolar interactions, captures the main experimental observations.