双光子跃迁中动态Stark位移对量子信息保真度的影响

Effects of Dynamic Stark Shift on Quantum Information Fidelity in Two-photon Transition

研究了相干态光场与原子的双光子相互作用中原子、光场和整个系统的量子信息保真度的时间演化,考察了光场引起能级的动态Stark位移对双光子过程中的量子信息保真度的影响.特别讨论了拉比振荡频率与光子数成线性关系的情况.结果表明,在拉比振荡频率线性化的情况下,量子信息保真度的演化表现出很好的周期性,周期与动态Stark位移参数有关.增强光强使保真度下降,失谐量的增加使保真度上升.

Evolutions of quantum information fidelity of atom, light field and system in two-photon processes are studied. Effects of dynamic Stark shift arising from light field on the fidelity of quantum information are investigated. In particular, the case in which frequency Rabi oscillations is a linear function of the photon number is discussed. It is shown that evolutions of fidelity reveal perfect periodicity and the periods are affected by dynamic Stark shift. Increasing the light intensity will decrease fidelity, and increasing detuning can improve fidelity.