Microwave Hanle effect in Rydberg atoms

An attempt was made to investigate how quantum interference of degenerate states affects the probabilities of transitions in single Rydberg atoms in the magnetic field. The absorption signals of the 37P3/2→37S1/2 transition were recorded in the scanned magnetic field. It was found that a microwave Hanle effect in Rydberg atoms significantly differ from that in low-excited atoms. The width of the resonances was determined by the spectral width of the resonant emission that always has the limited time of interaction with Rydberg atoms. The quantum beats accompanied the signals when the polarization of the exciting laser emission was orthogonal to the magnetic field, but disappeared when it was collinear with the field.