On-the-Spot Loading of Single-Atom Traps

TL;DR

This paper demonstrates that increasing the depth of static optical dipole traps significantly improves the loading efficiency and lifetime of single-atom traps, achieving nearly 80% filling ratio without atom rearrangement.

Contribution

It introduces a method to enhance single-atom trap loading and lifetime by increasing trap depth, enabling high filling ratios without atom rearrangement.

Findings

Achieved a trap lifetime of 7.9 seconds.

Demonstrated a filling ratio of 79% without rearrangement.

Extended loading times from 2.1 seconds to improve efficiency.

Abstract

Reconfigurable arrays of trapped single atoms are an excellent platform for the simulation of many-body physics and the realisation of high-fidelity quantum gates. The confinement of atoms is often achieved with focussed laser beams acting as optical dipole-force traps that allow for both static and dynamic positioning of atoms. In these traps, light-assisted collisions -- enhancing the two-atom loss rate -- ensure that single atom occupation of traps can be realised. However, the time-averaged probability of trapping a single atom is limited to $0.5$ when loading directly from a surrounding cloud of laser-cooled atoms, preventing deterministic filling of large arrays. In this work, we demonstrate that increasing the depth of a static, optical dipole trap enables the transition from fast loading on a timescale of $2.1\,$s to an extended trap lifetime of $7.9\,$s. This method demonstrates an achievable filling ratio of $(79\pm2)\,\%$ without the need of rearranging atoms to fill vacant traps.