在克尔媒质中原子和光场的量子信息保真度

Fidelity of Quantum Information for Atom and Field in Kerr Medium

讨论了在克尔媒质中原子与光场相互作用及拉曼相互作用时原子、光场和整个系统的量子信息保真度的时间演化过程。研究光场的光强、失谐量及克尔参量对保真度的影响。研究表明 ,当拉比振荡频率与光子数成正比时保真度表现出周期性的等幅振荡。光强的增加将使保真度下降 ,失谐量的增加会提高保真度 ,克尔媒质也对保真度的演化产生影响。失谐量为 0 ,克尔参量为 0 .5

The evolutions of quantum information for atoms, field and system in Kerr medium and Raman interaction are discussed. The effects of intensity of light, detuning parameters and Kerr coefficients on the fidelity are studied. It is shown that the evolutions of fidelity exhibit oscillations with equi-amplitude and perfect periodicity if the frequency of Rabi oscillation is the linear function of the photon number. Increasing the intensity of light will decrease the fidelity, and increasing the detuning parameters will improve the fidelity. Kerr coefficient affects the fidelity slightly and irregularly. The fidelity oscillates with equi-amplitude and perfect periodicity in the case of Δ=0, χ=0.5g and Raman interaction for degenerate levels.