Measuring Rapidities of a Bosonic Dipolar 1D Quantum Gas in Tonks and Super-Tonks Regimes

The distribution of rapidities—quasi-momenta of a one-dimensional (1D) many-body system that depends on the interactions within particles—are of great interest in characterizing many-body states. The bosonic 1D dipolar gas, with its integrability-breaking long-range interactions, is a perfect platform to explore rapidity distributions in a nearly integrable system. We report the measurement of rapidity distributions in a 1D dipolar quantum gas of dysprosium, where we use a Feshbach resonance to tune the short-range interaction strength and a magnetic field angle to tune the long-range dipole-dipole interaction sign and strength. In addition to ground state measurements, we also topologically pump the gas into super-Tonks regime to measure the rapidities of prethermal long-lived excited states (akin to many-body scar states).