Rb rotational mixtures*

The resonant dipole-dipole interaction between polar molecules occupying rotational states of opposite parities is a valuable resource for quantum simulation and quantum information processing. In this talk, we report the investigation on the strong resonant dipolar collisions of ultracold bosonic ²³Na⁸⁷Rb molecules, in the absence of external electric field. The dramatically enhanced two-body loss rate constants we measured are in good agreement with quantum close-coupling calculations. In addition, the dipolar strength can be tuned by preparing the NaRb mixture in different rotational levels. When the rotational level combination is not of the lowest energy, contributions from hyperfine changing collisions are also observed.