Fast long-distance transport of cold cesium atoms

TL;DR

This paper demonstrates rapid, efficient optical transport of cold cesium atoms over 43 cm in less than 30 ms using a moving lattice, enabling improved quantum simulation experiments with high atom retention and Bose-Einstein condensate generation.

Contribution

It introduces a high-speed optical transport method for cold atoms using a moving lattice generated by Bessel and Gaussian beams, achieving high efficiency and enabling quantum simulation applications.

Findings

Transport of 3 million atoms over 43 cm in under 30 ms

Transport efficiency of about 75% limited mainly by potential depth

Successful generation of a stable Bose-Einstein condensate with 20,000 atoms

Abstract

Transporting cold atoms between distant sections of a vacuum system is a central ingredient in many quantum simulation experiments, in particular in setups, where a large optical access and precise control over magnetic fields is needed. In this work, we demonstrate optical transport of cold cesium atoms over a total transfer distance of about $43\,$cm in less than $30\,$ms. The high speed is facilitated by a moving lattice, which is generated via the interference of a Bessel and a Gaussian laser beam. We transport about $3\times 10^6$ atoms at a temperature of a few $\mu$K with a transport efficiency of about $75\%$. We provide a detailed study of the transport efficiency for different accelerations and lattice depths and find that the transport efficiency is mainly limited by the potential depth along the direction of gravity. To highlight the suitability of the optical-transport setup for quantum simulation experiments, we demonstrate the generation of a pure Bose-Einstein condensate with about $2\times 10^4$ atoms. We find a robust final atom number within $2\%$ over a duration of $2.5\,$h with a standard deviation of $<5\%$ between individual experimental realizations.