Multipartite Entanglement Generation in a Structured Environment In this paper, we investigate the entanglement generation of nqubit states in a model consisting of n independent qubits, each coupled to a harmonic oscillator which is in turn coupled to a bath of N additional harmonic oscillators with nearestneighbor coupling. With analysis, we can find that the steady multipartite entanglement with different values can be generated after a longtime evolution for different sizes of the quantum system. Under weak coupling between the system and the harmonic oscillator, multipartite entanglement can monotonically increase from zero to a stable value. Under strong coupling, multipartite entanglement generation shows a speedup increase accompanied by some oscillations as nonMarkovian behavior. Our results imply that the strong coupling between the harmonic oscillator and the N additional harmonic oscillators, and the large size of the additional oscillators will enhance nonMarkovian dynamics and make it take a very long time for the entanglement to reach a stable value. Meanwhile, the couplings between the additional harmonic oscillators and the decay rate of additional harmonic oscillators have almost no effect on the multipartite entanglement generation. Finally, the entanglement generation of the additional harmonic oscillators is also discussed.

Dynamics of nonequilibrium thermal quantum correlation in a twoqubit Heisenberg XYZ model The nonequilibrium thermal entanglement and quantum discord in a twoqubit Heisenberg XYZ model subjected to two thermal baths with different temperatures are investigated. The dynamical behaviors of entanglement and quantum discord under the influences of the initial states of the twoqubit system, the temperature of the thermal baths and the coupling constant J_z are discussed. A special emphasis is devoted to study the effects of the thermal baths on the steady quantum correlation between the two qubits. Our results show that the temperature difference Delta T plays a key role for the appearance of steady quantum correlation, which can be enhanced by coupling constant J_z, DM interaction and nonuniform magnetic field.