利用Von Neumann量子约化熵理论,研究了共振情况下场与原子之间的耦合随时间和强度变化 时, Λ型三能级原子与单模场相互作用系统中量子场熵的演化特性,通过数值计算详细讨论了不同初始光场和耦合系 数变化的快慢对量子场熵的影响。结果表明:初始光场统计性质的不同将使系统的量子场熵演化发生较大变化,耦合强度调制函 数的变化将改变量子场熵演化曲线的振荡频率,场与原子相互作用的初始阶段是一个逐渐耦合的过程,原子叠加态概率使量子 场熵周期性地发生改变。

Based on the Von Neumann quantum reduced entropy theory, the evolution properties of field quantum entropy in the interaction system of Λ-type three-level atom and single-model field are investigated when the coupling between the field and the atom changes with time and intensity under the on-resonance condition. The influences of the different initial fields and changes of the coupling coefficient on field quantum entropy is discussed in detail through numerical calculation. Results show that the different statistical properties of the initial fields will lead to the great variation of the field quantum entropy, and the changes of the coupling strength modulation function will change the oscillating frequency of the field quantum entropy evolution. In addition, it is shown that the initial stage of the interaction between the field and atom is a gradually coupled procedure, and the superposition state probability of the atom makes the field quantum entropy change periodically.