Fast long-distance transport of cold cesium 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 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 $30\phantom{\rule{0.16em}{0ex}}\mathrm{ms}$. 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 $3\ifmmode\times\else\texttimes\fi{}{10}^{6}$ atoms at a temperature of a few microkelvins 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 a fast initial loss most likely due to the sudden onset of the acceleration and 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 $2\ifmmode\times\else\texttimes\fi{}{10}^{4}$ 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.