Classical correlation and quantum discord mediated by cavity in two coupled qubits
Classical correlation and quantum discord mediated by cavity in two coupled qubits
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DOI：
10.1088/0953-4075/44/1/015503
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发表时间：
2011-01
期刊：
影响因子：
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通讯作者：
Cheng-Zhi Wang;Chun-Xian Li;L. Nie;Jiang-Fan Li
中科院分区：
文献类型：
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作者：
Cheng-Zhi Wang;Chun-Xian Li;L. Nie;Jiang-Fan Li
研究了初始处于真空态、相干态和热平衡态的耦合二能级原子与腔场相互作用系统的经典关联和量子失谐动力学。考虑了原子-原子耦合与平均光子数之间的相互作用。我们发现，对于真空态的腔，经典关联或量子不和谐在演化过程中表现出突然的行为变化，并且对于零和非常大的量子比特-量子比特耦合周期性地演化。然而，对于相干态和热平衡态，当量子比特-量子比特耦合远大于平均光子数时，经典关联和量子不协将出现反常回复现象。随着量子比特间的耦合和平均光子数的增加，量子回复的周期变长。研究了系统中量子不和谐与纠缠的关系。
We study the dynamics of classical correlation and quantum discord of two coupled two-level atoms interacting with a cavity initially in vacuum, coherent and thermal equilibrium states, respectively. The interplay between the atom–atom coupling and mean number of photons is considered. We find that, for a cavity in a vacuum state, classical correlation or quantum discord shows a sudden change in behaviour during the evolution, and evolves periodically for zero and very large qubit–qubit couplings. However, for coherent and thermal equilibrium states, the classical correlation and quantum discord present the phenomenon of collapse–revival when the qubit–qubit coupling is much greater than the mean number of photons. The period of collapse–revival becomes long as the qubit–qubit coupling and mean number of photons increase. The relationship between quantum discord and entanglement in the studied system is considered.