Control of rubidium low-lying Rydberg states with trichromatic femtosecond π pulses for ultrafast quantum information processing

摘要

We propose an ultrafast femtosecond time scale trichromatic π-pulse illumination scheme for coherent excitation and manipulation of low-lying Rydberg states in rubidium. Selective population of nP_(3/2) levels with principal quantum numbers n < 12 using 75-fs laser pulses is achieved. The density-matrix equations of a four-level ladder system beyond the rotating-wave approximation have to be solved to clarify the balance between the principal quantum numbers, the duration of the laser pulses, and the associated ac-Stark effects for the fastest optimal excitation. The mechanism is robust for femtosecond control using different level configurations for applications in ultrafast quantum information processing and spectroscopy.