Doppler-induced spatially uniform atom-cavity coupling in a standing-wave cavity and the unidirectional momentum transfer on a moving atom

Deflection of an inverted two-state atom by a standing-wave cavity vacuum is analyzed. It is shown that clean vacuum Rabi oscillations occur at a frequency of $g_0/2\mathrm{}$ between the initial atom-field state and the state with the atomic transverse momentum displaced by $ħk$ if the cavity is tuned to the Doppler shift associated with the atomic motion along the cavity axis, given that the shift is much larger than the optimum atom-cavity coupling constant $g_0.$ Consequently, the atom can be deflected by the cavity, the direction of which is precisely controlled by the atom-cavity detuning.