Ehancement of quantum coherence and three-body entanglement by dynamical decoupling pulses

Abstract:

The influence of dynamical decoupling pulses on the quantum coherence, quantum entanglement and quantum discord in cavity quantum electrodynamics system is investigated. We find that the quantum coherence and non-classical correlations (entanglement and quantum discord) between two atoms can be increased by applying a train of dynamical decoupling pulses. Furthermore, by making use of the trace distance, we also explore the reason for enhancement of quantum coherence of two atoms. It is shown that the dynamical decoupling pulses can control and accelerate the return of quantum information from other subsystems to two atoms, and reduce the flow of quantum information between two atoms and other subsystems, which leads to the increase of quantum coherence and non-classical correlations between two atoms. Finally, we investigate the three-body entanglement of the system by using state preparation fidelity. It demonstrates that the genuine three-body entanglement may emerge in the system during the evolution of time. In particular, the period of emergence of three-body entanglement can be adjusted and enhanced by dynamical decoupling pulses.