Robustness of quantum discord to sudden death
Robustness of quantum discord to sudden death
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DOI：
10.1103/physreva.80.024103
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发表时间：
2009-08-01
影响因子：
2.9
通讯作者：
Villas-Boas, C. J.
中科院分区：
文献类型：
--
作者：
Werlang, T.;Souza, S.;Villas-Boas, C. J.
我们计算了马尔可夫环境下两量子比特量子不协和的耗散动力学。我们分析了不同的耗散通道，如退相、退极化和广义振幅衰减，假设每个量子比特都耦合到自己的通道。选择表现纠缠猝死的初始条件，我们比较了纠缠动力学和量子不协调动力学。结果表明，在纠缠突然消失的所有情况下，量子不协调仅在渐近极限内消失，其行为类似于量子比特的单个消相干，即使在有限的温度下也是如此。因此，量子不协调比纠缠与退相干的纠缠更稳健，因此仅基于量子不协调关联的量子算法可能比基于纠缠的算法更稳健。
We calculate the dissipative dynamics of two-qubit quantum discord under Markovian environments. We analyze various dissipative channels such as dephasing, depolarizing, and generalized amplitude damping, assuming independent perturbation, in which each qubit is coupled to its own channel. Choosing initial conditions that manifest the so-called sudden death of entanglement, we compare the dynamics of entanglement with that of quantum discord. We show that in all cases where entanglement suddenly disappears, quantum discord vanishes only in the asymptotic limit, behaving similarly to individual decoherence of the qubits, even at finite temperatures. Hence, quantum discord is more robust than the entanglement against decoherence so that quantum algorithms based only on quantum discord correlations may be more robust than those based on entanglement.