论文标题
量子通信的高斯错误通道和测量的限制
Constraints on Gaussian Error Channels and Measurements for Quantum Communication
论文作者
论文摘要
两个量子系统的联合高斯测量值可用于远程各方之间的量子通信，例如传送或纠缠交换协议。整个协议中的许多类型的物理误差源可以通过在测量之前作用的独立高斯错误通道来建模。在这项工作中，我们研究了两种模式上的联合高斯测量值$ \ mathsf {a} $和$ \ mathsf {b} $在独立的单模式高斯错误通道之后进行，例如，参数$ l_ \ m _ \ mathsf {a} $ and $ l_ \ mathsf {b} $ N_ $ N_ $ n_ $ n_ \ mathsf {b} $。我们表明，对于任何高斯测量，如果$ l_ \ Mathsf {a} + l_ \ Mathsf {B} + N_ \ Mathsf {a} + N_ \ Mathsf {b} \ geq 1 $，则有效的总测量是可分开的，并且不适合传送或结构化的仲裁进ptuteptation或Enterange Intapping satpate satpate satpate intuptation satpate satpate satpate satpate satpation satpate satpate satpate satpation satpation tupt。如果不满足这种不平等，则存在一个不可分割的高斯测量值。我们扩展结果并确定一对单模高斯误差通道对，这些误差通道使所有高斯测量值可分开。
Joint Gaussian measurements of two quantum systems can be used for quantum communication between remote parties, as in teleportation or entanglement swapping protocols. Many types of physical error sources throughout a protocol can be modeled by independent Gaussian error channels acting prior to measurement. In this work we study joint Gaussian measurements on two modes $\mathsf{A}$ and $\mathsf{B}$ that take place after independent single-mode Gaussian error channels, for example loss with parameters $l_\mathsf{A}$ and $l_\mathsf{B}$ followed by added noise with parameters $n_\mathsf{A}$ and $n_\mathsf{B}$. We show that, for any Gaussian measurement, if $l_\mathsf{A} + l_\mathsf{B} + n_\mathsf{A} + n_\mathsf{B} \geq 1$ then the effective total measurement is separable and unsuitable for teleportation or entanglement swapping of arbitrary input states. If this inequality is not satisfied then there exists a Gaussian measurement that remains inseparable. We extend the results and determine the set of pairs of single-mode Gaussian error channels that render all Gaussian measurements separable.
