Non-Markovian Entanglement Dynamics In Coupled Superconducting Qubit Systems

In recent years, the quantum information and quantum computing research made a lot ofprogress. The core of quantum computing is the control of quantum systems as the hardware forscientific computing, information processing and quantum simulation. Josephson junction showsthe huge potential. Another core resource to the realization of quantum information is quantumentanglement, it has become clear that entanglement is a new resource for tasks that cannot beperformed by means of classical resources. So for the comprehension and application ofquantum entanglement becomes increasingly important.The first part simply introduced the concept of quantum entanglement and the researchprogress for superconducting quantum qubits. To describe the decoherence that result ofenvironment, we use quantum master equation method. Without using the weak couplingapproximation and the Non-Markovian approximation, we understand the interaction betweenquantum system and the environment comprehensively.The second part we study entanglement transfer and entanglement dynamics about openquantum system and environments. Considering two entangled qubits interacting withindependent environment, two entangled qubits occur sudden death and entanglement suddenbirth appear between two environments. We mainly construct the entanglement transfer amongqubits, and find that the two reservoirs have an intermediate effects in the transfer process.Based on the model of coupled superconducting quantum qubit systems, we analyze theentanglement generation and dynamics in non-Markovian regime by the concurrence method forthe last part. It is shown that the concurrence is determined by the initial state and the couplingconstant of the system, the entanglement time can be prolonged by adjusting coherenceparameters in non-Markovian environment, and ensure the achievement for the application inquantum computation and quantum information.