双模压缩真空态在Tavis-Cummings模型中量子态保真度

Fidelity of quantum states of two-mode squeezed vacuum state in Tavis-Cummings model

考虑了原子的偶极相互作用,通过计算Tavis-Cummings模型下压缩真空态的保真度,阐明了在双模压缩真空态与环境(原子)通过双光子发生相互作用过程中量子信息的保真程度随时间的演化关。通过计算机模拟出两原子处于各种初态下时原子、光场和系统的保真度随时间的演化图象,分析出三者在压缩指数r、偶极相互作用常数ga和相位(?)等改变时的变化情况,结果表明r和k值的改变对于提高保真度具有重要意义。当两原子处于基态时减小r和当两原子处于一Bell基时增大都可以显著的提高体系的保真度。

The dipole-dipole interaction of the two atoms is discussed. By considering the interaction between the two-mode squeezing vacuum state field and the environment （atoms）,we investigate the quantum information fidelities of the atoms the field and the system in two- mode squeezing vacuum state Tavis-Cummings model. With the help of the computer simulation, the time evolution of fidelity of system, atoms and field is obtained. The result is indicate that r and k are important to the fidelity of the quantum information. When the two atoms are initially in the groud state, decreasing r can increase the three fidelities. On the contrary, when the two atoms are initially in one of the Bell states, increasing r can increase the three fidelites.