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arXiv · 2507.03623

Shaping Cold Atom Clouds with a Vortex Beam

Arianna Bertoluzza·Sonja Lorenz·Paul Hampp·Moriz Härle·Daniel Braun·David Petrosyan·József Fortágh·Andreas Günther
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Abstract

We introduce a method for shaping a cold atom cloud using a vortex laser beam with a polarization singularity at its center, which creates a point of vanishing intensity. Exploiting this feature we experimentally demonstrate two different schemes to create micron-scaled line- and sheet-like atomic density distributions. In the dynamic scheme, atoms in the bright beam regions are accelerated and therefore effectively removed from the cloud. In the dark-state scheme, these atoms are pumped into a state that does not interact with the shaping light. In both cases, an atomic distribution remains, either as a thin line or as a sheet when an additional polarizer is used. We find good agreement between the experimental results and our theoretical model, which predicts the method to be in principle not diffraction-limited, paving the way for studies of phenomena arising in unconfined atomic ensembles on the micrometer scale.

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Arianna Bertoluzza, Sonja Lorenz, Paul Hampp, Moriz Härle, Daniel Braun, David Petrosyan, József Fortágh, Andreas Günther. 2025-07-04. Shaping Cold Atom Clouds with a Vortex Beam. https://doi.org/10.1103/bqys-81lw

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