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arXiv · 2507.19157

Probing the spatial distribution of k-vectors in situ with Bose-Einstein condensates

Samuel Gaudout·Rayan Si-Ahmed·Clément Debavelaere·Menno Door·Pierre Cladé·Saïda Guellati-Khelifa
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Abstract

We present a novel method for mapping \textit{in situ} the spatial distribution of photon momentum across a laser beam using a Bose-Einstein condensate (BEC) as a moving probe. By displacing the BEC, we measure the photon recoil by atom interferometry at different positions in the laser beam and thus reconstruct a two-dimensional map of the local intensity and effective dispersion of the $k$ wave vector. Applied to a beam diffracted by a diaphragm, this method reveals a local \textit{extra recoil} effect, which exceeds the magnitude $h\nu/c$ of the individual plane-waves over which the beam can be decomposed. This method offers a new way to precisely characterize wavefront distortions and to evaluate one of the major systematic bias sources in quantum sensors based on atom interferometry.

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Samuel Gaudout, Rayan Si-Ahmed, Clément Debavelaere, Menno Door, Pierre Cladé, Saïda Guellati-Khelifa. 2025-07-25. Probing the spatial distribution of k-vectors in situ with Bose-Einstein condensates. https://arxiv.org/abs/2507.19157

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