On Rabi oscillations in ground hyperfine states of 87 Rb atom driven by a microwave field

We have observed the Rabi oscillations of the population of 87 Rb atoms in the hyperfine ground state, when a cold atom cloud prepared in the hyperfine ground state (F = 1) was exposed to a microwave (MW) radiation field resonant to the |F = 1, m F = 0 > → |F = 2, m F = 0 > transition. After exposure to MW field, the atom cloud was imaged using the absorption probe method, and the cloud images have revealed that the population excited to the hyperfine state (F = 2) varied with the position in the atom cloud. At a given position in the atom cloud, the excited population shows Rabi oscillations between two hyperfine states with an increase in the MW field exposure time. Using these Rabi oscillations, the amplitude of the microwave magnetic field was estimated, which showed good agreement with the calculated field values. PACS numbers: 32.80.Pj, 33.55.Be, 67.85.-d.