Alternating current Zeeman and Stark interference effect in Ramsey separated oscillating fields

Analytic expressions have been derived of the alternating current (ac) Zeem an and ac Stark effect in an atomic beam magnetic resonance method using Ra msey separated oscillating fields. An interesting feature which will affect the normal Ramsey pattern is that an interference fringe is superimposed o n the dispersion lineshapes of the normal ac Zeeman or ac Stark effect. We point out that this nerv character of ac Zeeman (ac Stark) effect generally exists in all kinds of Ramsey method, for example, in the optical Ramsey a tomic interferometer and atomic beam frequency standard. An important impli cation is that, particularly in an atomic beam frequency standard using Ram sey method, this effect has an influence on the evaluation of the second-or der Doppler frequency shift.