位相损耗腔中简并双光子拉曼耦合系统中的熵特性

研究了简并双光子拉曼耦合过程中存在位相损耗时,光场原子系统线性熵、光场线性熵和原子线性熵的特性,讨论了原子相干性和光场平均光子数对各线性熵的影响.结果表明:由于位相损耗的存在使系统的线性熵除初始时刻为零外,其他时刻均大于零,且与原子初始状态无关,即原子相干性对系统线性熵没有影响.当原子初始处于激发态或基态时,原子线性熵呈现出较完美的周期性;而在原子初始处于激发态和基态的叠加态时,原子的线性熵始终为零.随光场平均光子数的增加,各线性熵均会增大.关键词：位相损耗简并双光子拉曼耦合过程线性熵

Entropy property of degenerate Raman two-photon coupling system in a phase-damping cavity

The properties of linear entropies for atom-field coupling system for atom and for field in the system are investigated via degenerate Raman two-photon coupling processes in a phase-damping cavity.The influences of atomic coherence and mean photon number on all the linear entropies are discussed.The results show the the existence of cavity phase damping leads to the phenomenon that the linear entropy of the system is larger than zero except the initial time and independent of the atomic initail preparation.When the atom is initially in its excited state or ground state,the linear entropy of the atom show nearly perfect periodicity.But when the atom initially in its superporsition state of ground state and excited state,the linear entropy of the atom is equal to zero .With the increase of mean photon number,all the linear entropies increase.