单模辐射场与两个二能级原子相互作用过程中的熵特性

Entropy property in the system of a single-mode field interacting with two two-level atoms

在大失谐条件下,研究了一位于能量损耗腔中两个二能级原子与单模辐射场相互作用系统中,原子-光场系统线性熵、原子线性熵和光场线性熵的时间演化特性,讨论了两原子的初始状态、腔场衰减常数以及光场的平均光子数对各线性熵的影响。结果表明:当两原子均处于激发态或基态时,各线性熵始终为零;而当两原子初始均处于激发态与基态的相干叠加态时,腔场损耗使得系统演化为混合态,原子线性熵和光场线性熵作振幅逐渐减小的周期振荡。

The time evolution of linear entropy of atom-field coupling system, atom and field in the system of two two-level atoms inside a single-mode cavity with amplitude-damping under the condition of large detuning were investigated. The effects of the initial preparation of two atoms, the decay rate of cavity field and the mean photon number of field on all kinds of linear entropy were discussed. The results show that if both the two atoms are in their excited states or ground states, all the linear entropies equal to zero. But when the two atoms are in their coherent superposition state of excited state and ground state, the cavity dissipation will lead to the system to evolve into a mixed state, the linear entropy of atom and field exhibits periodic oscillations with damped amplitude.