摘要
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 k Hz.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 574.21 Hz/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 below10^(-14),surpassing the long-term stability of current cold-atom CPT clocks.
作者
Chang Zhan
Zhu Ma
Jiatao Wu
Maojie Li
Chengyin Han
Bo Lu
Chaohong Lee
詹畅;马翥;吴嘉涛;李懋捷;韩成银;鹿博;李朝红(Laboratory of Quantum Engineering and Quantum Metrology,School of Physics and Astronomy,Sun Yat-sen University,Zhuhai 519082,China;Institute of Quantum Precision Measurement,State Key Laboratory of Radio Frequency Heterogeneous Integration,Shenzhen University,Shenzhen 518060,China;College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China;Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area,Shenzhen 518045,China)
基金
supported by the National Key Research and Development Program of China (No. 2022YFA1404104)
the National Natural Science Foundation of China (Nos. 12025509 and 12104521)。
