Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, CEP 13083-859, Campinas, São Paulo, Brazil.
Phys Rev Lett. 2011 Jul 8;107(2):020502. doi: 10.1103/PhysRevLett.107.020502. Epub 2011 Jul 5.
We relate the problem of irreversibility of entanglement with the recently defined measures of quantum correlation--quantum discord and one-way quantum deficit. We show that the entanglement of formation is always strictly larger than the coherent information and the entanglement cost is also larger in most cases. We prove irreversibility of entanglement under local operations and classical communication for a family of entangled states. This family is a generalization of the maximally correlated states for which we also give an analytic expression for the distillable entanglement, the relative entropy of entanglement, the distillable secret key, and the quantum discord.
我们将纠缠的不可逆性问题与最近定义的量子相关性度量——量子失谐和单方向量子亏损联系起来。我们表明，纠缠的形成总是严格大于相干信息，而且在大多数情况下纠缠代价也更大。我们证明了在局部操作和经典通信下，一类纠缠态的纠缠是不可逆的。这个家族是最大关联态的推广，我们还给出了可提取纠缠、纠缠的相对熵、可提取秘密密钥和量子失谐的解析表达式。
