论文标题
改善三方不确定性与量子记忆的关系
Improved tripartite uncertainty relation with quantum memory
论文作者
论文摘要
不确定性原理是与经典力学区分的量子力学中的惊人和基本特征。它提供了一个重要的下限，以预测两个在粒子上测量的两个任意不相容的可观察物的结果。在量子信息理论中，这种不确定性原理通常用熵进行。在这里，我们提出了三方量子 - 内存辅助熵不确定性关系的改进。不确定性的下限是通过考虑相互信息和孔值数量来得出的。它表明，该方法得出的结合将比[物理学中的下限都更紧。莱特牧师。 103，020402（2009）]。 Furthermore, regarding a pair of mutual unbiased bases as the incompatibility, our bound will become extremely tight for the three-qubit $\emph{X}$-state system, completely coinciding with the entropy-based uncertainty, and can restore Renes ${\emph{et al.}}$'s bound with respect to arbitrary tripartite pure states.此外，通过应用我们的下限，可以达到量子秘密密钥速率的更严格的界限，这对于增强量子密钥分布协议的安全性至关重要。
Uncertainty principle is a striking and fundamental feature in quantum mechanics distinguishing from classical mechanics. It offers an important lower bound to predict outcomes of two arbitrary incompatible observables measured on a particle. In quantum information theory, this uncertainty principle is popularly formulized in terms of entropy. Here, we present an improvement of tripartite quantum-memory-assisted entropic uncertainty relation. The uncertainty's lower bound is derived by considering mutual information and Holevo quantity. It shows that the bound derived by this method will be tighter than the lower bound in [Phys. Rev. Lett. 103, 020402 (2009)]. Furthermore, regarding a pair of mutual unbiased bases as the incompatibility, our bound will become extremely tight for the three-qubit $\emph{X}$-state system, completely coinciding with the entropy-based uncertainty, and can restore Renes ${\emph{et al.}}$'s bound with respect to arbitrary tripartite pure states. In addition, by applying our lower bound, one can attain the tighter bound of quantum secret key rate, which is of basic importance to enhance the security of quantum key distribution protocols.
