Entanglement Properties Of The Coupled Qubits With Non-Markovian Environment

Quantum entanglement is one of the most striking feature in quantum physics. It is the most important basic resources in quantum information, is also the cornerstone of the realization of quantum communication and quantum computer, and is able to verify the basic problems of quantum mechanics. In recent years, the progress of theory and experiment tell us that quantum entanglement is theessential resources for quantum information processing, such as quantum teleportation, quantum dense coding, etc. The detailed content and structure is as follows:In the first chapter, we reviewed the production and the development of quantum information,introduced the research status and progress of Quantum entanglement Systematically。In the second chapter, we simply introduced the Superconducting qubits based on the Josephson junction, The basic theory of quantum entanglement, Density matrix theory and the simple derivation of master equation.In the third chapter, with non-Markovian environment,by using certain initial conditions, we discussed the entanglement characteristics of coupled superconducting qubits with the impact for the interaction of system and coupled qubits inσx direction, found that, for the initial two entangled qubits, the entanglement sudden death phenomenon(ESD) will occurs in the reservoir, and the occurs of ESD is strongly dependent on the environment. We also found that if the initial state is maximally entangled mixed state(MEMS), without the interaction between qubits in phase relaxation process, the decay of entanglement will be faster.In the fourth chapter, with non-Markovian environment,by using certain initial conditions, we discussed the entanglement characteristics of coupled superconducting qubits with the impact for the interaction of system and coupled qubits inσz direction. We found that the entanglement degree is strongly related with the initial quantum state and the coupling between the qubits and the environment. And the interaction between the qubits and the environment suppreses the decay of the entanglement. The ESD can be prevented by choosing the adymmetric coupling between the qubits and the environment.In the last chapter,we make brief summary and prospects of the work in this paper.