二能级原子SU(2)压缩的混态临界性质

The Mixed--State Critical Properties in SU(2)Squeezing of Two--Level Atom

本文研究初始纯态演化的二能级原子SU(2)压缩的混态临界行为。通过建立赝自旋单位球模型引入混态概念,求出了SU(2)压缩的混态临界值。对于受驱动阻尼二能级原子系统,借助于数值计算较详细地讨论了偏调和阻尼参数对SU(2)压缩的混态临界值、混态压缩的“寿命”以及压缩的最大量值的影响。

In this paper, the mixed--state critical behavior in SU(2) squeezing of two-level atom with initial pure state evolution are studied. The conception of mix-ed--state is introduced by setting up a model of pseudospin vector unit sphere.A mixed--state critical value of SU(2) squeezing is given. For the system of adriven damped two--level atom, the damping parameter and detuning of the sys-tem effect on the mixed--state critical value, lifetime, and maximum value ofthe SU(2) squeezing are discussed in detail by means of numerical calculation.