利用非幺正性增强相位协变信道性能
Enhancing phase-covariant channel performance with non-unitality
AI总结：
该研究分析相位协变信道的量子通信特性与非幺正程度的关系，推导相关解析公式，提出非幺正性度量方法，证实非幺正性能提升信道保真度与输出纯度，还可延长甚至重生量子纠缠。
摘要：
我们分析了相位协变信道的量子通信特性与其非幺正程度的关联。具体而言，我们推导了纯态下信道最小与最大保真度、以及最大输出纯度的解析公式。接着，我们提出了一种非幺正性度量方式，并说明可通过量子信道的经典混合在幺正映射与最大非幺正映射间调整。最后，我们证明最大保真度和最大输出纯度随非幺正性提升而增大，并给出若干示例。值得注意的是，非幺正性还能延长量子纠缠存续时间，甚至引发纠缠重生。
英文摘要：
We analyze quantum communication properties of phase-covariant channels depending on their degree of non-unitality. In particular, we derive analytical formulas for minimal and maximal channel fidelity on pure states and maximal output purity. Next, we introduce a measure of non-unitality and show how to manipulate between unital and maximally non-unital maps by considering classical mixtures of quantum channels. Finally, we prove that maximal fidelity and maximal output purity increase with non-unitality and present several examples. Interestingly, non-unitality can also prolong quantum entanglement and lead to its rebirth.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
