arXiv:1201.1029 · Physical Review A
Complete population transfer in a three-state quantum system by a train of pairs of coincident pulses
Andon A. Rangelov, Nikolay V. Vitanov
Abstract
A technique for complete population transfer between the two end states $|1\ensuremath{\rangle}$ and $|3\ensuremath{\rangle}$ of a three-state quantum system with a train of $N$ pairs of resonant and coincident pump and Stokes pulses is introduced. A simple analytic formula is derived for the ratios of the pulse amplitudes in each pair for which the maximum transient population ${P}_{2}(t)$ of the middle state $|2\ensuremath{\rangle}$ is minimized, ${P}_{2}^{\mathrm{max}}={\mathrm{sin}}^{2}(\ensuremath{\pi}/4N)$. It is remarkable that, even though the pulses are on exact resonance, ${P}_{2}(t)$ is damped to negligibly small values even for a small number of pulse pairs. The population dynamics resembles generalized $\ensuremath{\pi}$ pulses for small $N$ and stimulated Raman adiabatic passage for large $N$ and therefore this technique can be viewed as a bridge between these well-known techniques.