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 cont... 展开 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. 收起