Single atom counting in a two-color magneto-optical trap
Abstract
Recording the fluorescence of a magneto-optical trap (MOT) is a standard tool for measuring atom numbers in experiments with ultracold atoms. When trapping few atoms in a small MOT, the emitted fluorescence increases with the atom number in discrete steps, which allows to measure the atom number with single-particle resolution. Achieving such single particle resolution requires stringent minimization of stray light from the MOT beams, which is very difficult to achieve in experimental setups that require in-vacuum components close to the atoms. Here, we present a modified scheme that addresses this issue: Instead of collecting the fluorescence on the MOT (D2) transition, we scatter light on an additional probing (D1) transition and collect this fluorescence with a high-resolution microscope while filtering out the intense MOT light. Using this scheme, we are able to reliably distinguish up to 17 K atoms with an average classification fidelity of 95 \%.
Cite
@article{arxiv.2011.10081,
title = {Single atom counting in a two-color magneto-optical trap},
author = {Martin Schlederer and Alexandra Mozdzen and Thomas Lompe and Henning Moritz},
journal= {arXiv preprint arXiv:2011.10081},
year = {2021}
}