Ablation loading of barium ions into a surface electrode trap

Abstract: Trapped-ion quantum information processing may benefit from qubits encoded in isotopes that are practically available in only small quantities, e.g. due to low natural abundance or radioactivity. Laser ablation provides a method of controllably liberating neutral atoms or ions from low-volume targets, but energetic ablation products can be difficult to confine in the small ion-electrode distance, micron-scale, microfabricated traps amenable to high-speed, high-fidelity manipulation of ion arrays. Here we investigate ablation-based ion loading into surface-electrode traps of different sizes to test a model describing ion loading probability as a function of effective trap volume and other trap parameters. We demonstrate loading of ablated and photoionized barium in two cryogenic surface-electrode traps with 730 $\mu$m and 50 $\mu$m ion-electrode distances. Our loading success probability agrees with a predictive analytical model, providing insight for the confinement of limited-quantity species of interest for quantum computing, simulation, and sensing.