Protecting entanglement from decoherence using weak measurement and quantum measurement reversal
Protecting entanglement from decoherence using weak measurement and quantum measurement reversal
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DOI：
10.1117/12.2024442
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发表时间：
2011-12
期刊：
影响因子：
19.6
通讯作者：
Yong-Su Kim;Jong-Chan Lee;O. Kwon;Yoon-Ho Kim
中科院分区：
文献类型：
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作者：
Yong-Su Kim;Jong-Chan Lee;O. Kwon;Yoon-Ho Kim
量子态与其环境之间不可避免的耦合导致退相干。弱测量——在不干扰的情况下间接观察量子态——现在被证明是减少甚至消除退相干效应的有用工具。退相干通常是由于与环境不可避免的耦合而引起的，它会导致量子相干性的退化。对于多部量子系统，退相干导致纠缠的退化，在某些情况下，导致纠缠猝死2,3。因此，处理退相干是量子信息中面临的一个关键问题，因为纠缠是许多量子信息应用的重要资源，包括量子计算、量子密码学、量子隐形传态和量子计量学。在这里，我们提出并演示了一种保护纠缠不受退相干影响的方案。我们的纠缠保护方案利用量子测量本身主动对抗退相干，可以有效地避免纠缠猝死。
The unavoidable coupling between a quantum state and its environment leads to decoherence. Weak measurements—indirectly observing a quantum state without disturbing it—are now shown to be a useful tool for reducing or even nullifying the effects of decoherence. Decoherence, often caused by unavoidable coupling with the environment, leads to degradation of quantum coherence1. For a multipartite quantum system, decoherence leads to degradation of entanglement and, in certain cases, entanglement sudden death2,3. Tackling decoherence, thus, is a critical issue faced in quantum information, as entanglement is a vital resource for many quantum information applications including quantum computing4, quantum cryptography5, quantum teleportation6,7,8 and quantum metrology9. Here, we propose and demonstrate a scheme to protect entanglement from decoherence. Our entanglement protection scheme makes use of the quantum measurement itself for actively battling against decoherence and it can effectively circumvent even entanglement sudden death.