Magnetically Induced Atomic Transitions of the Potassium D-2 Line

Magnetically induced (MI) transitions of the D-2 line of K-39 atom in an external magnetic field of 10-600 G have been experimentally and theoretically investigated for the first time using circularly polarized sigma(+) and sigma(-) radiations. According to the selection rules, the transitions between the sublevels of the ground and excited levels of a hyperfine structure with F-e - F-g = Delta F = +/- 2 are forbidden in the zero magnetic field, whereas their probabilities increase radically in a magnetic field. For the F-g = 1 -> F-e = 3 (Delta F = +2) and F-g = 2 -> F-e = 0 MI transitions, the highest probabilities are achieved using the sigma(+) and sigma(-) radiations, respectively. The atomic transitions have been spectrally resolved using selective reflection of laser radiation from a nanocell filled with potassium atomic vapor, which makes it possible to investigate the behavior of the MI transitions. The experimental and theoretical data are shown to be in good agreement.