Entanglement dynamics of n-qubit states in a hierarchical environment

In this paper, we will investigate the entanglement dynamics of n-qubit states in a hierarchical environment which contains a single-mode cavity and a reservoir of an infinite number of modes. Our results imply that the time evolution of entanglement depends not only on the coupling strength between the system and the single-mode cavity but also on the correlation time of the reservoir which has no direct interaction with the states. With analysis, we find that the entanglement dynamics exhibits different behaviors in a parameter space depicted by the coupling strength and the correlation time of the reservoir. The effect of the size of the system on the pairwise entanglement is analyzed and the entanglement generation is discussed.