大失谐腔QED中任意初态双原子系统的量子信息保真度

运用全量子理论研究了大失谐腔QED中任意初态(纯态和混合态)两全同二能级原子的量子信息保真度.讨论了系统初态和原子耦合程度对量子信息保真度的影响;揭示了保真度演化的物理实质.结果表明,系统的保真度呈周期性演化,保真度演化的振幅的受原子混合度的调制,演化周期受原子耦合系数的控制.恰当选取两原子的初态、控制好相互作用时间,可以获得系统量子信息的高保真输出,产生在量子信息处理中有广泛应用的周期量子回声.

The quantum information fidelity of two-atom systems of arbitrary initial states in QED cavity under high detuned

By means of the full quantum theory,we investigate the fidelity of quantum informationin an arbitrary(pure and mixed) states of the two identical atoms system in highly detunedcavity QED,the influence of the initial state of systems and the degree of the atoms coupledon the fidelity of quantum information is discussed,and the physical properties of the fidelityevolution is revealed.It is showed that the fidelity of systems evolves periodic,the amplitudeof the fidelity evolution is modulated by the mixture of the atoms,and the evolution frequencyis controlled by the degree of atoms coupled.Choose a suitable initial state of the two-atomscoupled parameter and controlling the interaction time properlyone can get a high fidelityoutput,and emerge periodic quantum echo.