Long distance optical conveyor-belt transport of ultracold $^{133}$Cs and $^{87}$Rb atoms

TL;DR

This paper demonstrates a fast, efficient optical conveyor belt system for transporting ultracold cesium and rubidium atoms over 37.2 cm in under 25 ms, suitable for quantum gas microscopy applications.

Contribution

It introduces a method using static Gaussian beams for long-distance atom transport with high efficiency, avoiding complex beam shaping techniques.

Findings

Achieved transport of up to 7 million atoms with 75% efficiency.

Optimized transport trajectory using minimum jerk for minimal atom loss.

Successfully produced Bose-Einstein condensates after transport.

Abstract

We report on the transport of ultracold cesium and rubidium atoms over $37.2\,$cm in under $25\,$ms using an optical conveyor belt formed by two counter-propagating beams with a controllable frequency difference that generate a movable optical lattice. By carefully selecting the waists and focus positions, we are able to use two static Gaussian beams for the transport, avoiding the need for a Bessel beam or vari-focus lenses. We characterize the transport efficiency for both species, including a comparison of different transport trajectories, gaining insight into the loss mechanisms and finding the minimum jerk trajectory to be optimum. Using the optimized parameters, we are able to transport up to $7 \times 10^6$ cesium or rubidium atoms with an efficiency up to $75\,$%. To demonstrate the viability of our transport scheme for experiments employing quantum gas microscopy, we produce Bose-Einstein condensates of either species after transport and present measurements of the simultaneous transport of both species.