二项式光场与级联三能级原子在非旋波近似下相互作用的量子特性

Quantum Properties of the Binomial Field Interacting with a Cascade Three-level Atom Beyond the Rotating Wave Approximation

利用全量子理论,在非旋波近似下,对与级联型三能级原子相互作用的二项式光场的光场压缩效应和原子布居几率进行了精确求解.讨论了二项式光场参量η对光场压缩效应的影响,同时也讨论了二项式态光场的最大光子数M对原子布居几率的影响.数值计算结果表明:随着二项式光场参量η的增大,光场压缩效应的持续时间先增大后减小.在非旋波近似下,由于虚光子的影响,光场压缩效应的演化曲线出现了"小锯齿状"的振荡;随着二项式光场的最大光子数M的增大,原子布居几率回复塌缩周期逐渐增大,并且原子布居几率在塌缩区不能完全塌缩,而是出现了"小锯齿状"的振荡.另外文中也讨论了非旋波项对系统量子特性的影响.

The squeezing effect and atomic population of the binomial field interacting with a cascade three level atom are calculated accurately without rotating-wave approximation(without RWA) by using the complete quantum theory.The influences of the binomial state field parameter η on the field squeezing effect and the maximum photon number M of the binomial state field on the atomic population are considered.The results obtained from using the numerical method show that with increase of the binomial state field parameter η,the duration of the squeezing effect increases at first and then decreases.The little indentation oscillation appears in the evolution curves of the field squeezing effect,which is caused by virtual photon without RWA.The period of the revival-collapse increases with the increase of the maximum photon number M,and the atomic population can not collapse completely in the collapse regime,but displays little indentation oscillation.In addition the influence of the without-RWA terms on the quantum properties of the system are discussed.