Chinese Physics Letters
Optimal Control of Population Transfer in Three-Level System with Genetic Algorithms
Xiangyun Zhang, Zhenrong Sun, Guoliang Chen, Zugeng Wang, Zhizhan Xu, Ruxin Li
Abstract
Population transfer in a three-level Λ system is simulated numerically and optimized. Almost complete population transfer from |1⟩ to |3⟩ is achieved by a genetic algorithm while the population in state |2⟩ reached minimum over the entire evolution at the same time. The result shows that the optimal pulse sequence is the well-known stimulated Raman adiabatic passage (STIRAP) scheme. The detuning of pump pulse and Stokes pulse Δ p and Δ s with the opposite sign and the chirps χ p and χ s with the same sign are in favour of the complete and robust population transfer for few-cycle laser pulse. Rabi frequencies Ω p and Ω s have insensitive effects on the complete population transfer during a large scope of their ratio when they are large enough.