Quantum correlations generation and distribution in a universal covariant quantum cloning circuit

• Published in: Science China. Information sciences Vol. 60; no. 12; pp. 244 - 251
• Main Author: Ren, Xijun
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.12.2017; Springer Nature B.V
• Subjects: Asymmetry; Circuits; Cloning; Computer Science; Correlation; Information Systems and Communication Service; Quantum entanglement; Qubits (quantum computing); Research Paper; 协变; 和分布; 广义; 操作能力; 电路; 量子克隆; 量子关联; 量子纠缠; quantum discord; genuine multipartite quantum correlation; universal covariant quantum cloning circuit; quantum information; quantum correlation
• ISSN: 1674-733X; 1869-1919
• DOI: 10.1007/s11432-016-0569-2

We discussed the distribution and generation of quantum correlations in a universal covariant quantum cloning circuit. Specifically, we first considered the distribution of quantum correlation, i.e., quantum discord, among the four qubits of the circuit. Then, we analyzed the generation of genuine 3-or 4-qubit entanglement in the cloning process. It is found that the circuit generates genuine 4-qubit GHZ（GreenbergerHorne-Zeilinger）-type state while only W-type 3-qubit state could be generated. These results illustrate the special quantum correlation manipulation capabilities of the cloning circuit.