Mechanism of entanglement preservation

作者:Tong, Qing-Jun*; An, Jun-Hong; Luo, Hong-Gang; Oh, C. H.
来源:Physical Review A, 2010, 81(5): 052330.
DOI:10.1103/PhysRevA.81.052330

摘要

We study the entanglement preservation of two qubits locally interacting with their reservoirs. We show that the existence of a bound state of the qubit and its reservoir and the non-Markovian effect are two essential ingredients and their interplay plays a crucial role in preserving the entanglement in the steady state. When the non-Markovian effect is neglected, the entanglement sudden death (ESD) is reproduced. On the other hand, when the non-Markovian is significantly strong but the bound state is absent, the phenomenon of the ESD and its revival is recovered. Our formulation presents a unified picture about the entanglement preservation and provides a clear clue on how to preserve the entanglement in quantum information processing.