Fidelity of Quantum States in the Jaynes-Cummings Model with a Time-varying Frequency Field
频率变化场J-C模型中的量子态保真度

Using the Jaynes-Cummings model, the dynamical properties of the fidelity of quantum states in the system that consists of a two-level atom interacting with a single-mode field are studied. The frequency of the field varying with time in the form of sine has been considered. The results obtained by numerical calculations show that the time-evolution behavior of the fidelities of field and system are not influenced by the frequency variation of field, but the time-evolution behavior of the fidelity of atom is modulated by the frequency variation of field. The larger the amplitude of the field frequency variance is, the stronger modulation interaction of the field frequency variance is. When the amplitude is larger than a fixed value, the time-evolution behavior of the fidelity of atom will display periodic oscillation behavior.Its oscillation period is in agreement with the period of frequency varying.