Investigations into quantum correlation of coupled qubits in a squeezed vacuum reservoir

• Published in: Chinese physics B 2013-02, Vol.22 (2), p.86-91
• Main Author: 嵇英华 刘咏梅
• Format: Article
• Language: English
• Subjects: Amplitudes; Correlation; Death; Entanglement; Joining; Qubits (quantum computing); Reservoirs; 关联耦合; 挤压参数; 最大纠缠态; 水库; 混合状态; 真空; 量子位; 量子关联
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/22/2/020305

In this paper,we investigate the quantum correlation of coupled qubits which are initially in maximally entangled mixed states in a squeezed vacuum reservoir.We compare and analyze the effects of squeezed parameters on quantum discord and quantum concurrence.The results show that in a squeezed vacuum reservoir,the quantum discord and quantum concurrence perform with completely opposite behaviors with the change of squeezed parameters.Quantum discord survives longer with the increase of squeezed amplitude parameter,but entanglement death is faster on the contrary.The results also indicate that the classical correlation of the system is smaller than quantum discord in a vacuum reservoir,while it is bigger than quantum discord in a squeezed vacuum reservoir.The quantum discord and classical correlation are more robust than quantum concurrence in the two reservoir environments,which indicates that the entanglement actually is easily affected by decoherence and quantum discord has a stronger ability to avoid decoherence in a squeezed vacuum reservoir.