Optical Traps for sympathetic Cooling of Ions with ultracold neutral Atoms

TL;DR

This paper demonstrates a method to trap and sympathetically cool ions and neutral atoms using optical traps without RF fields, overcoming RF trap limitations and enabling new ultracold chemistry and many-body physics experiments.

Contribution

The authors introduce an optical trapping technique for ions and neutral atoms that eliminates RF-induced heating, allowing efficient sympathetic cooling and broad applicability.

Findings

Achieved trapping of Rb atoms and Ba+ ions in a shared optical potential.

Demonstrated cooling of Ba+ ions from 370 μK to 100 μK via collisions.

Overcame RF trap limitations, enabling new ultracold chemistry studies.

Abstract

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.