Entanglement is one of essential quantum resources in quantum information processing, playing an important role during quantum communication and computation. While any system unavoidably interacts with its surrounding environment, this thus will result in decoherence or dissipation effect. With this in mind, a natural question arises: how to recover quantum entanglement under decoherence inducing by the environmental noises. In this work, our attempt is to propose an effective strategy to optimally achieve entanglement recovery. Specifically, we derive a nontrivial condition satisfied by any operation U, i.e. , which will definitely recover the entanglement of an arbitrary two-qubit system, and more importantly offer an explicit physical explanation towards the intrinsic mechanics of the entanglement recovery. By means of derivations, we obtain the appropriate operational strength to realize optimal entanglement recovery through taking advantage of our proposed methods. As illustrations, we apply some local operations complying with our presented strategy on validly protecting entanglement, including -symmetry operation, quantum weak measurement and quantum reversal measurement.

纠缠是量子信息处理中必不可少的量子资源之一，在量子通信和计算中发挥着重要作用。虽然任何系统都不可避免地与其周围环境相互作用，但这将导致退相干或耗散效应。考虑到这一点，一个自然的问题出现了：如何在环境噪声引起的退相干下恢复量子纠缠。在这项工作中，我们试图提出一种有效的策略来最佳地实现纠缠恢复。具体来说，我们推导出任何操作U满足的非平凡条件，即，这肯定会恢复任意两个量子位系统的纠缠，更重要的是为纠缠恢复的内在机制提供明确的物理解释。通过推导，我们获得了适当的操作强度，通过利用我们提出的方法来实现最佳纠缠恢复。作为说明，我们应用了一些符合我们提出的有效保护纠缠策略的局部操作，包括 -对称操作、量子弱测量和量子反转测量。