Final Published Version
Physical Review A
We present a detailed experimental study of the frequency-modulated excitation of a two-level atom, using a microwave field to drive transitions between two Rydberg Stark states of potassium. In the absence of a modulation the interaction is the standard model of the Rabi problem, producing sinusoidal oscillations of the population between the two states. In the presence of a frequency modulation of the interacting field, however, the time evolution of the system is significantly modified, producing square wave oscillations of the popula- tion, sinusoidal oscillations at a different frequency, or even sinusoidal oscillations built up in a series of stair steps. The three responses described above are each found in a different regime for the frequency of the modulation with respect to the unmodulated Rabi frequency: the low-, high-, and intermediate-frequency regimes, respectively.
© 1998 by the American Physical Society. The publisher's version of the article can be found at http://journals.aps.org/pra/abstract/10.1103/PhysRevA.58.2265
Michael W. Noel, W. M. Griffith, and T. F. Gallagher, "Frequency Modulated Excitation of a Two-Level Atom," Phys. Rev. A 58, 2265 (1998).