| Quantum coherence and quantum correlation are important features of quantum mechanics,which is the unique way of expression of quantum world different from the classical world.They are the most basic resources in quantum information processing,and can achieve various quantum tasks.Recently,coherence is taken as a quantum resource,and a rigorous theoretical framework to describe it has been put forward.Measuring quantum coherence has become a reality.The study of quantum coherence has attracted wide attention of physical researchers.Due to the inevitable interaction with the environment in the evolution of quantum system,the decoherence of quantum resources leads to the limitation of the application of quantum resources in quantum tasks.Therefore,the study of dynamical evolution of quantum resources(quantum entanglement,quantum discord,quantum coherence)with different environment models,and taking programs to reduce the decay of quantum resources or protect quantum resources have become particularly important,which can deepen the understanding of the basic concepts of quantum resources,and promote the application of quantum resources in practical quantum information.The contents of this paper include the following aspects.1.Based on the cavity quantum electrodynamics(QED)theory,first,the dynamics of quantum entanglement and quantum discord of two moving atoms going through a single mode cavity one after another is investigated.Effects of the initial atom states,the photon number in cavity field and the atomic movement on quantum entanglement and quantum discord are analyzed,and the method to improve quantum entanglement and quantum discord of the system is given.The dynamical evolution behavior of quantum entanglement and quantum discord is compared,it is found that in some cases,the evolution law of quantum entanglement and quantum discord is consistent.Second,the dynamics of quantum entanglement and quantum discord of two atoms going through a two-mode cavity one after another is investigated.The influence of the two-mode entangled fields on the quantum entanglement and quantum discord is discussed.2.We investigate the quantum coherence and quantum entanglement dynamics of a classical driven single atom coupled to a single-mode cavity.It is shown the transformation between the atomic coherence and the atom-field entanglement exists,and can be improved by adjusting the classical driving field.The joint evolution of two identical single-body systems is also studied.The results show the quantum coherence transfers among composite subsystems,and the coherence conservation of composite subsystems has been obtained.Moreover,a case of cavity field as dissipative cavity is considered,and the classical driving field can be used to suppressthe decay of the coherence and entanglement due to considering the leaky cavity.At last,the non-Markovian dynamics of system is discussed.The results show there is a positive association between the non-Markovianty and coherence or entanglement.3.The exact dynamics of an open quantum system consisting of one qubit driven by the classical driving field is investigated.Our attention is focused on the influences of single-and two-photon excitations on the dynamics of quantum coherence and quantum entanglement.It is shown that the atomic coherence can be improved or even maintained by the classical driving field,the non-Markovian effect and the atom-reservoir detuning.The interconversion between the atomic coherence and the atom-reservoir entanglement exists,and the amount of interconversion can be controlled by the appropriate conditions.The case of two atom-heat reservoir is also studied,and the conservation of coherence for different partitions is explored.The system with two-photon excitations contains more abundant physical meaning,and its dynamics is different from the case of single-photon excitation.4.The interaction of a cavity field(heat reservoir)and single atom driven by the classical driving field is extended to a pair of separate cavities(heat reservoir)with a single atom inside each one.The dynamics of quantum coherence,quantum entanglement and quantum discord of two atoms with the atom-cavity field model and the atom-heat reservoir model is discussed.For the atom-cavity field model,we give the way to protect quantum coherence,quantum discord and quantum entanglement.It is found that in some cases,the evolution curves of three kinds of quantum resources are similar or even the same.For the atom-heat reservoir model,the methods of protecting three kinds of quantum resources are given with the Markovian environment and the non-Markovian environment. |
