采用Negativity度量两子系统间的纠缠,研究了两个全同二能级原子与腔相互作用系统中的量子纠缠。考虑原子与腔场失谐相互作用,并且原子间存在偶极相互作用的情况。利用数值计算方法,讨论了失谐量和偶极相互作用强度变化对量子纠缠的影响。研究结果表明:随失谐量增大和偶极相互作用强度增大,两原子间纠缠增强。另一方面,随失谐量逐渐增大,两原子间纠缠呈现出从不规则振荡向准周期性振荡转变。随偶极相互作用强度增大,原子间纠缠振荡频率加快。

Negativity was adopted to quantify the degree of entanglement between two subsystems. We researched the situation that two identical two-level atoms are trapped in a single-mode optical cavity, and each atom off-resonantly interacted with cavity field via a one-photon hopping. Under a dipole-dipole interaction between atoms, the entanglement dynamics between two atoms was studied. The influence of detuning between atom and cavity and the strength of dipole-dipole interaction of two atoms on the entanglement between atoms were discussed. The results obtained using the numerical method show that the entanglement between atoms is strengthened with the increase of the detuning, and it is also strengthened with increase of the strength of dipole-dipole interaction of two atoms. On the other hand, the entanglement between atoms exhibits a transformation from irregular oscillations to quasi-periodic oscillations with the increase of the detuning, and its oscillation frequency is accelerated with the increase of the strength of dipole-dipole interaction between two atoms.