Nonlinear phenomena occurring during interaction between an atom and a strong rf field of resonant or nonresonant frequency are reviewed. The account is given in both semiclassical and consistently quantummechanical languages. The concept of an atom ``dressed by the radiation field'' in which not only the optical-frequency field but also the radio-frequency field is quantized is presented in detail. The results are summarized of theoretical and experimental studies of multiphoton transitions, radiative shifts of normal magnetic resonance lines, parametric resonance, and coherent resonances under the conditions of optical pumping. The influence of nonresonance rf fields on magnetic properties and the rate of magnetic relaxation of atoms is discussed.

RT Journal
T1 Nonlinear and parametric effects in atomic rf spectroscopy
A1 Novikov,L.N.
A1 Skrotskii,G.V.
PB Physics-Uspekhi
PY 1978
FD 10 Jul, 1978
JF Physics-Uspekhi
JO Phys. Usp.
VO 21
IS 7
SP 589-610
DO 10.1070/PU1978v021n07ABEH005666
LK https://ufn.ru/en/articles/1978/7/c/