Quantum Field Entropy In A System Of Moving Atom Interacting With The Single Or Double Modes Optic Field

The development in quantum optics and in quantum information is summarized in the paper at first. The quantum noiseless coding method is discussed with the quantum entropy theory, and the capacity of quantum channel. Secondly, the evolution properties of quantum field entropy are studied in the system of moving atom interacting with the field. It shows that the field entropy is oscillating, which is the result of the correlation property between the atom and field. With the increase of the initial field intensity, which is the initial mean photon number the oscillation becomes irregularly and the amplitude decreases. The atom and the field couples tighter, and the disorder parameter decreases. The double modes optic field makes the periodicity decreases and the mean entropy increases. Thirdly, the entropy squeezing properties is discussed in the system of moving three-level atom interacting with the field, which shows that the effect of continuous entropy squeezing can be realized with the proper parameters in the system. In the last, the entropy evolution is discussed on the system of coupling atom interacting with the single mode optics in Kerr medium. It shows that the activation of atom changes the time of the atom to the field, which makes the field entropy not the same as the past classical model. With the increase of Kerr medium parameter, the field entropy decreases gradually. And the mean value of field entropy decreases, the evolution periodicity increases, when the coupling atom strengthens.The deep research on the properties of the quantum entropy evolution and the entropy squeezing in a system of moving atom interacting with the optic field not only constitutes the theoretic foundation of the quantum telecommunication, but also the further research on the amount of self-information, amount of mutual information, the capacity of quantum channel and the code rate.