准Λ型四能级中用非匹配高斯脉冲实现相干布居转移

Coherent Population Transfer in a Four-Level Quasi-Lambda System Driven by Unmatched Gaussian Pulses

文章研究用非匹配高斯脉冲实现四能级准Λ型系统中的相干布居转移。从密度矩阵方程出发,对四个态的布居数随时间的演化进行了数值模拟。模拟结果表明,泵浦光场的拉比频率强度和失谐量对布居转移率的影响和探测光场、耦合光场的拉比频率强度及失谐量对布居转移率的影响不同;自发辐射诱导相干(SGC)对布居转移率的影响不大。但当它们选取适当参数的时候,基态的布居几乎可以全部被转移到目标态能级。

The population transfer in a four-level quasi-lambda system driven by unmatched Gaussian pulses is investigated.By using the matrix equation theory,evolutions of the populations of the four states Vs time is investigated.Numerical simulations show that the Rabi frequency intensity and detuning of pumping field have different effects on the population transfer comparing with the probe and coupling field;and spontaneously generated coherence（SGC）have little effect on population transfer.If the parameters are chosen appropriately,population can be transferred almost completely to the target state.