自发辐射诱导原子质心运动退相干的理论研究

摘要

The decoherence dynamics of a two-level atom coupled into a vacuum electromagnetic field are studied .The analytic solution of the Schrodinger equation has been given , and then the reduced den-sity matrix for the motion of the atomic center of mass has been derived .It is shown that spontaneous e-mission induces the entanglement between the atomic spatial motion and the atomic electronic states , which induces the spatial quantum decoherence of the atom .The decoherence factor is given , and its properties , such as dynamical evolution with time and evolution for different atomic positions , are demon-strated by some figures .%研究单个二能级原子与真空电磁场的相互作用，给出了总系统的薛定谔方程的解析波函数，并分析得出原子质心运动的约化密度矩阵。结果表明原子内部电子态与真空场的相互作用会诱导原子的质心运动与原子的内部电子态发生纠缠，从而会导致原子的质心运动发生量子退相干。文中还给出了退相干因子的解析表达式，并通过图形演示了原子质心运动退相干的动力学演化情况，以及与原子的空间尺度和原子-场耦合强度的相关性。