Evaluating capacities of quantum channels is the first purpose of quantum Shannon theory, but in most cases the task proves to be very hard. Here, we introduce the set of Multi-level Amplitude Damping quantum channels as a generalization of the standard qubit Amplitude Damping Channel to quantum systems of finite dimension d. In the special case of d = 3, by exploiting degradability, data-processing inequalities, and channel isomorphism, we compute the associated quantum and private classical capacities for a rather wide class of maps, extending the set of models whose capacity can be computed known so far. We proceed then to the evaluation of the entanglement assisted quantum and classical capacities.

评估量子通道的容量是量子香农理论的首要目的，但是在大多数情况下，任务非常艰巨。在这里，我们介绍了多级幅度阻尼量子通道的集合，作为标准量子位幅度阻尼通道到有限维d量子系统的推广。在d  = 3的特殊情况下，通过利用可降解性，数据处理不等式和通道同构，我们为相当大的一类图计算了相关的量子和私有经典容量，从而扩展了可以计算其容量的模型集至今。然后，我们进行对纠缠辅助量子和经典能力的评估。