运用全量子理论,研究了在相干光场作用下双光子通道中具有任意初态(纯态和混合态)原子比特周期量子回声的产生条件.通过分别考察原子比特初态和环境参数对其保真度演化的影响,获得了产生和调控原子比特周期量子回声参数,并分析了它的物理实质,为实现量子信息高保真输出提供了一种可能的理论依据.“,”By means of the full quantum theory,the conditions of generating a periodical quantum echo in the two-photon channel of a atom bit with arbitrary(pure or mixed) initial states was investigated,in coherent light field.Having studied the effects both the atom bit initial state and the surroundings parameter on its fidelity evolution,respectively,the pa-rameter for control the periodical quantum echo of the atom bit was got and discuss its physical characters was discussed,that may be as a possible theoretical basis to the realization of a high fidelity output of quantum information.