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arXiv:1912.05689

Preparation of mesoscopic atomic ensembles with single-particle resolution

Andreas Hüper, Cebrail Pür, Hetzel, M., Jiao Geng, J. Peise, I. Kruse, Kristensen, M., W. Ertmer, J. Arlt, Carsten Klempt

Published Dec 11, 2019• 1 citation
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Abstract

The analysis of entangled atomic ensembles and their application for interferometry beyond the standard quantum limit requires an accurate determination of the number of atoms. We present an accurate fluorescence detection technique for atoms that is fully integrated into an experimental apparatus for the production of many-particle entangled quantum states. Single-particle resolving fluorescence measurements for $1$ up to $30$ atoms are presented. According to our noise analysis, we extrapolate that the single-atom resolution extends to a limiting atom number of $390(20)$ atoms. We utilize the accurate atom number detection for a number stabilization of the laser-cooled atomic ensemble. For a target ensemble size of $7$ atoms prepared on demand, we achieve a $92(2)\,\%$ preparation fidelity and reach number fluctuations $18(1)\,\mathrm{dB}$ below the shot noise level using real-time feedback on the magneto-optical trap.

DOI
10.48550/arxiv.1912.05689

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The analysis of entangled atomic ensembles and their application for interferometry beyond the standard quantum limit requires an accurate determination of the number of atoms. We present an accurate fluorescence detection technique for atoms that is fully integrated into an experimental apparatus for the production of many-particle entangled quantum states. Single-particle resolving fluorescence measurements for 111 up to 303030 atoms are presented. According to our noise analysis, we extrapolate that the single-atom resolution extends to a limiting atom number of 390(20)390(20)390(20) atoms. We utilize the accurate atom number detection for a number stabilization of the laser-cooled atomic ensemble. For a target ensemble size of 777 atoms prepared on demand, we achieve a 92(2) %92(2)\,\%92(2)% preparation fidelity and reach number fluctuations 18(1) dB18(1)\,\mathrm{dB}18(1)dB below the shot noise level using real-time feedback on the magneto-optical trap.
Abstract The analysis of entangled atomic ensembles and their application for interferometry beyond the standard quantum limit requires an accurate determination of the number of atoms. We present an accurate fluorescence detection technique for atoms that is fully integrated into an experimental apparatus for the production of many-particle entangled quantum states. Number-resolved fluorescence measurements with single-atom accuracy for 1 up to 30 atoms are presented. According to our noise analysis, we extrapolate that the single-atom accuracy extends to a limiting atom number of 390(20) atoms. We utilize the accurate atom number detection for a number stabilization of the laser-cooled atomic ensemble. For a target ensemble size of 7 atoms prepared on demand, we achieve a 92(2)% preparation fidelity and reach number fluctuations 18(1) dB below the shot noise level using real-time feedback on the magneto-optical trap.
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Many cold atom experiments rely on precise atom number detection, especially in the context of quantum-enhanced metrology where effects at the single particle level are important. Here, we investigate the limits of atom number counting via resonant fluorescence detection for mesoscopic samples of trapped atoms. We characterize the precision of these fluorescence measurements beginning from the single-atom level up to more than one thousand. By investigating the primary noise sources, we obtain single-atom resolution for atom numbers as high as 1200. This capability is an essential prerequisite for future experiments with highly entangled states of mesoscopic atomic ensembles.
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