Quantum theory of Rayleigh scattering

We develop a quantum theory of atomic Rayleigh scattering. Scattering is considered as relaxation incident photons from selected mode free space to the reservoir other modes. Additional excitations states which appear are treated scattered light. show that an entangled state excited atom and photon formed during Due entanglement, never completely absorbed by atom. even if frequency incommensurable with any transition frequency, light spectrum has maximum at mode. The linewidth much smaller than spontaneous emission single atom, therefore, process can be elastic. developed does not use phenomenological concept virtual level.