Shaping cold-atom clouds with a vortex beam
Phys. Rev. A 113, 023102 – Published 3 February, 2026
DOI: https://doi.org/10.1103/bqys-81lw
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 sheetlike 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.
