Gaussian and sinc-shaped few-cycle-pulse-driven ultrafast coherent population transfer in Λ-like atomic systems

We report and propose a simple scheme to achieve efficient and fast coherent population transfer by utilizing either a nonlinearly chirped Gaussian-shaped few-cycle laser pulse or an unchirped sinc-shaped few-cycle laser pulse. The proposed scheme is shown to be fairly robust against the variation of the laser parameters such as temporal pulse width, chirp rates, carrier-envelope phases, and Rabi frequencies. We find that compared to the so-called stimulated Raman adiabatic passage technique, our scheme for complete population transfer with few-cycle Gaussian-shaped laser pulses requires less pulse area.