标题： 纠缠变换的误差指数从退化中 显示英文标题

标题： Error exponents for entanglement transformations from degenerations

摘要： 本文探讨了纯多体态之间渐近LOCC变换中速率与强逆指数之间的权衡关系。 任何单个拷贝的概率变换都意味着可以以指数下降的成功概率实现速率为1的渐近变换。 然而，可能存在以非零概率实现渐近变换的情况，但在任何有限数量的拷贝上，即使允许概率性变换，也无法以相同速率实现变换。 在这些情况下，尚不清楚最优成功概率是呈指数下降还是更快。 证明渐近变换可行性的一个基本工具是退化。 任何退化都会产生一个序列的随机LOCC变换，从初始状态的拷贝加上次线性数量的GHZ态转换为相同数量的目标状态拷贝。 这些协议包含可以自由选择的参数，但参数的选择会影响成功概率。 在本文中，我们表征了参数的渐近最优选择，并推导出相应协议的误差指数的单字母表达式。 特别是，这表明当随机变换来源于退化时，成功概率存在指数下界。 显示英文摘要

摘要： This paper explores the trade-off relation between the rate and the strong converse exponent for asymptotic LOCC transformations between pure multipartite states. Any single-copy probabilistic transformation between a pair of states implies that an asymptotic transformation at rate 1 is possible with an exponentially decreasing success probability. However, it is possible that an asymptotic transformation is feasible with nonzero probability, but there is no transformation between any finite number of copies with the same rate, even probabilistically. In such cases it is not known if the optimal success probability decreases exponentially or faster. A fundamental tool for showing the feasibility of an asymptotic transformation is degeneration. Any degeneration gives rise to a sequence of stochastic LOCC transformations from copies of the initial state plus a sublinear number of GHZ states to the same number of copies of the target state. These protocols involve parameters that can be freely chosen, but the choice affects the success probability. In this paper, we characterize an asymptotically optimal choice of the parameters and derive a single-letter expression for the error exponent of the resulting protocol. In particular, this implies an exponential lower bound on the success probability when the stochastic transformation arises from a degeneration.