Spatially Resolved Temperature Measurement Using Rydberg Doppler Broadening Thermometry
Abstract
We demonstrate a technique for spatially resolved temperature measurement utilizing Rydberg Doppler broadening thermometry. This method employs two focused laser beams arranged perpendicularly to excite laser-cooled atoms from the ground state to a Rydberg state via two photon absorption process. Temperature is obtained through the Doppler broadening of the spectral line. The perpendicular configuration allows for selective probing of a specific position within the atomic cloud, enabling localized temperature measurement. This technique, in principle, offers a temperature resolution on the order of \SI{}{\nano\kelvin}, attributed to the exceptionally narrow natural linewidth of the involved rubidium Rydberg transition line. Furthermore, the setup enables the measurement of position-velocity correlations within the cold atom ensemble. The velocity information is extracted through the Doppler shift, whereas the spatial information is inferred from the arrival time of ions detected by a channel electron multiplier detector. We use our method to measure the local temperature in a magneto-optical trap.
Cite
@article{arxiv.2604.28002,
title = {Spatially Resolved Temperature Measurement Using Rydberg Doppler Broadening Thermometry},
author = {K. N. Trivedi and M. Carminati and Èlia Solé Cardona and T. Bonaccorsi and R. Donofrio and B. Bégoc and O. Morsch},
journal= {arXiv preprint arXiv:2604.28002},
year = {2026}
}
Comments
Corrected minor text in the abstract; Replaced the sentence "Using this technique, for the first time, we observed the spatial temperature gradient within the atomic cloud, with higher temperature in the wings and lower temperature in the center" with "We use our method to measure the local temperature in a magneto-optical trap"