Controlling on Entangled Decoherence by the Interaction Model Between Qubit and Environment

Abstract

The entangling evolution of the coupled qubits interacting with non-Markov environment is investigated in terms of concurrence. The results show that the entanglement of quantum systems depends on not only the initial state of system but also the coupling ways between qubit and environment. It shows that: (1) when the system is initially in \(( | 00 \rangle\pm| 11 \rangle)/\sqrt{2}\) state or in the mixed state which is produced by the state, if we can control the coupling between the qubits and the environment in a asymmetrical state, we can make the quantum system always in the entangled state. (2) For an initial state \(( | 01 \rangle\pm| 10 \rangle)/\sqrt{2}\) or in its mixed state, in contrast, there will not be entangled death under the symmetric coupling. We also find that, in \(( | 01 \rangle\pm| 10\rangle)/\sqrt{2}\) or in its mixed state, the stronger the interaction between qubits is, the better to struggle against entanglement sudden death is.