High fidelity source of single atoms in the quantum ground state of optical tweezers

Summary form only given. Complete control of individual atoms trapped in far-off resonance optical tweezers is vital for gaining a better understanding of the microscopic world. It will provide a platform with unprecedented flexibility for studying few-body physics, and might lead to new quantum technologies. By combining near-deterministic preparation of single atoms [1-3] with Zeeman-insensitive Raman sideband cooling [4], we present a push button method to prepare a single 85Rb atom in its centre of mass ground state with high fidelity. Our Raman sideband cooling scheme works efficiently in an environment with magnetic field fluctuations that were too large for other Raman sideband cooling variations [5,6]. In 2D, we achieve a fidelity for the entire loading procedure of ~0.7 for a single atom in the ground state of the optical tweezers. In 3D, the fidelity drops to 0.1 since the cooling is less efficient for the weakly confined tweezer axis.