Exact time evolution of a 4-qubit system in a common reservoir and its influence on bipartite entanglement dynamics

Abstract

We obtain the exact evolution of 4 qubits interacting with its neighbors and are immersed in a common reservoir. From the exact solution, the dynamics of entanglement between two arbitrary qubits is studied. A steady-state concurrence is obtained that is proportional to the qubit- reservoir coupling and the initial conditions. It is also found that due to the presence of the other qubits, the bipartite entanglement is not lost asymptotically to the environment.