Coherent population transfer among Rydberg states by subpicosecond, half-cycle pulses

Abstract

Ultrashort, unipolar electric-field pulses have been used to coherently redistribute population between Rydberg states in sodium. The population in several Rydberg states is recorded simultaneously as a function of peak field. In addition, two temporally separated pulses have been used to interferometrically characterize the redistribution process. In the lowest fields, the experimental results are in agreement with the predictions of lowest-order perturbation theory. At slightly higher fields, still well below the ionization threshold, the redistribution process becomes nonperturbative, and a numerical integration of the time-dependent Schr\"odinger equation must be used to achieve partial agreement between theory and experiment.