Optical Traps for sympathetic Cooling of Ions with ultracold neutral Atoms

We report the trapping of ultracold neutral \( \text{Rb}\) atoms and \( \text{Ba}^+ \) ions in a common optical potential in absence of any radiofrequency (RF) fields. We prepare \( \text{Ba}^+ \) at \( 370 ~ \mu K \) and demonstrate efficient sympathetic cooling by \(100 ~ \mu K \) after one collision. Our approach is currently limited by the \( \text{Rb}\) density and related three-body losses, but it overcomes the fundamental limitation in RF traps set by RF-driven, micromotion-induced heating. It is applicable to a wide range of ion-atom species, and may enable novel ultracold chemistry experiments and complex many-body dynamics.