调制振幅对粒子布居几率振荡的影响

Effect of modulated amplitude on oscillation of population probability

为探讨调频场导致的量子效应的物理本质,运用密度矩阵方程和布洛赫矢量模型,对调频场作用下二能级原子系统中的粒子布居几率振荡现象进行了理论分析,讨论了光场调制振幅对振荡过程的影响。理论计算结果表明,光场调制振幅对粒子布居转移和几率振荡有较大的调制作用。当其他参量不变时,随着调制振幅的增大,粒子布居几率振荡减弱,布居转移效率增高,吸收增强。布洛赫矢量分析表明,该振荡过程是系统粒子数转移、吸收和极化三者之间的动态变化过程。

To explore the physical mechanism induced by a frequency-modulated light field,the phenomenon of the oscillation of population probability in a two-level system under a frequency-modulated field is analyzed theoretically by means of the density matrix equation and Bloch vector model.The effect of the modulated amplitude on the process of the oscillation is also discussed.The results show that the oscillation of population probability and population transfer is modulated by the modulated amplitude.Increasing the modulated amplitude when the other parameters are fixed,the oscillation of population probability is weakened,and the efficiency of population transfer and the absorption are enhanced.The analysis in Bloch vector model shows that the population oscillation reflects the dynamic transformation process among the population transfer,absorption and polarization in the quantum system.