Generation and protection of steady-state quantum correlations due to quantum channels with memory

• Published in: Quantum information processing 2016-12, Vol.15 (12), p.5129-5144
• Main Authors: Guo, You-neng, Fang, Mao-fa, Wang, Guo-you, Zeng, Ke
• Format: Article
• Language: English
• Subjects: Channels; Correlation; Damping; Data Structures and Information Theory; Depolarization; Dynamics; Mathematical Physics; Physics; Physics and Astronomy; Quantum Computing; Quantum entanglement; Quantum Information Technology; Quantum Physics; Quantum theory; Qubits (quantum computing); Ratio analysis; Spintronics; Steady state
• ISSN: 1570-0755; 1573-1332
• DOI: 10.1007/s11128-016-1442-5

We have proposed a scheme of the generation and preservation of two-qubit steady-state quantum correlations through quantum channels where successive uses of the channels are correlated. Different types of noisy channels with memory, such as amplitude damping, phase damping, and depolarizing channels, have been taken into account. Some analytical or numerical results are presented. The effect of channels with memory on dynamics of quantum correlations has been discussed in detail. The results show that steady-state entanglement between two initial qubits whose initial states are prepared in a specific family states without entanglement subject to amplitude damping channel with memory can be generated. The entanglement creation is related to the memory coefficient of channel μ . The stronger the memory coefficient of channel μ is, the more the entanglement creation is, and the earlier the separable state becomes the entangled state. Besides, we compare the dynamics of entanglement with that of quantum discord when a two-qubit system is initially prepared in an entangled state. We show that entanglement dynamics suddenly disappears, while quantum discord dynamics displays only in the asymptotic limit. Furthermore, two-qubit quantum correlations can be preserved at a long time in the limit of μ → 1 .