Origins of the intrinsic noise of zero-field metastable helium-4 optically pumped magnetometers
Phys. Rev. A 114, 012619 – Published 22 July, 2026
DOI: https://doi.org/10.1103/m7zt-mmr1
Abstract
We report a comprehensive characterization of the intrinsic noise of a single-beam -based vector optically pumped magnetometer, and identify its main origins. In its optimal regime, the sensor provided vector magnetic readings with noise below on two axes. We show that photon shot noise dominates at the optimum, and that the standard quantum limit set by spin projection of the aligned ensemble lies around . An extra noise is observed on one axis. It fits well with our model of metastable atom transit, suggesting interesting links with spin-noise spectroscopy.
