Research On The Character Of Light And Atoms By Enhanced Raman Scattering

Due to the straightforward procedures and good characteristics in the experiment, stimulated Raman scattering has been widely used in quantum information storage, precision measurement and etc. When the Raman scattering process reacts with the scattering matter, it will produce coherence between the scattering matters. Especially, because of the longer coherence time in the atomic ensemble, the characteristic of Raman scattering in atomic ensemble has very important meaning. In this paper, we do the corresponding theoretical research on the process of the realization of two-mode squeezed state between photons and atoms, as well as the Raman scattering process of slow light effect.Firstly, we introduce the methods to improve the conversion efficiency of light field by the atomic spin wave or injection of a seed light field,the seed light is correlated with the initially prepared atomic spin stimulate. Secondly, this paper theoretically calculates the quantum fluctuations of the quadrature components of the two-mode photon-atom quantum interface.We found that the enhanced Raman scattering based on quantum interface method just can improve the initial photon-atom squeezing slightly. But the correlation enhanced Raman scattering can prepare stronger photon-atom squeezing. Such a strong two-mode squeezed state has very important applications in precision measurement research.Thirdly, due to the interaction between light and the atomic ensemble, the refractive index of material will change in the enhanced Raman scattering processes, and the changing index will call the change in group velocity of light wave because of the relationship between group velocity and the the refractive index. And, we put forward a new theory to explain the phenomenon of slow light by enhanced Raman scattering,...