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Chinese Optics Letters

Magnetic field stabilization system designed for the cold-atom coherent population-trapping clock

Zhan Chang, Zhu Ma, Jiatao Wu, Maojie Li, Chengyin Han, Bo Lü, Chaohong Lee

Published Jan 1, 2024• 5 citations
Publisher

Abstract

Accurate control of magnetic fields is crucial for cold-atom experiments, often necessitating custom-designed control systems due to limitations in commercially available power supplies.Here, we demonstrate precise and flexible control of a static magnetic field by employing a field-programmable gate array and a feedback loop.This setup enables us to maintain exceptionally stable current with a fractional stability of 1 ppm within 30 s.The error signal of the feedback loop exhibited a noise level of 10 -5 A•Hz -1/2 for control bandwidths below 10 kHz.Utilizing this precise magnetic field control system, we investigate the second-order Zeeman shift in the context of cold-atom coherent population-trapping (CPT) clocks.Our analysis reveals the second-order Zeeman coefficient to be 574.21Hz/G 2 , with an uncertainty of 1.36 Hz/G 2 .Consequently, the magnetic field stabilization system we developed allows us to achieve a second-order Zeeman shift below 10 -14 , surpassing the long-term stability of current cold-atom CPT clocks.

DOI
10.3788/col202422.080202

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