부산대학교 도서관

We investigate the dynamical evolution of the global quantum discord (GQD) and the von Neumann entropy (VNE) of a moving two-, three-, and four two-level atomic system (TLS) (N=2,3,4). These systems interact with a single-mode Fock and coherent fields in the cavity under the influence of the Stark effect. According to the evolution of the GQD and VNE, quantum correlations for both the Fock and coherent fields decrease with an increase in the Stark parameter. Quantum correlations deplete more rapidly in the presence of coherent field as compared to the Fock field with increasing value of the Stark parameter. The maximum amount of quantum entanglement that the quantum system can achieve with an increase in the Stark shift parameter is seen to decrease more quickly in the presence of the Fock field than it does in the coherent field. Moreover, the large N systems are more prone to the increasing values of the Stark shift parameter. The GQD increases with the number of atoms N for both the Fock and the coherent field while the VNE increases only with the Fock field. Additionally, it has been found that for the larger N atomic systems, atomic motion has no effect on the period of entanglement oscillations as the number of atoms increases. Periodic behavior for the GQD and VNE is seen for both the initial mixed and pure states in the presence of the Stark shift for the Fock and coherent fields, respectively.