We suggest a quantum description of Rayleigh light scattering on atoms. We show that an entangled state of the excited atom and the incident photon is formed during the scattering. Due to entanglement, a photon is never completely absorbed by the atom. The formation of the scattering spectrum is considered as a relaxation of incident photons to the reservoir of free space modes that are in thermal equilibrium. Additional excitations of the reservoir modes occurring during scattering are treated as scattered light. We show that even if the frequency of incident photons is incommensurate with an atomic transition frequency, the scattered light spectrum has a maximum at the frequency of incident photons. In addition, the linewidth of the scattered light is much smaller than that of the spontaneous emission of a single atom. Therefore, the process can be considered as elastic.

中文翻译：

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瑞利散射的量子理论

我们建议对原子上的瑞利光散射进行量子描述。我们表明，在散射过程中形成了激发原子和入射光子的纠缠态。由于纠缠，光子永远不会被原子完全吸收。散射光谱的形成被认为是入射光子松弛到处于热平衡状态的自由空间模态的储库。散射过程中发生的储层模态的其他激发被视为散射光。我们表明，即使入射光子的频率与原子跃迁频率不相称，散射光谱在入射光子的频率处也具有最大值。另外，散射光的线宽比单个原子的自发发射的线宽小得多。因此，