标题： 量子过程的可恢复性的基本限制 显示英文标题

标题： Fundamental limitations on the recoverability of quantum processes

摘要： 量子信息处理和计算任务可以被理解为量子网络，包括量子态和信道以及它们可能的物理变换。 因此，估计量子过程在经历物理变换时信息内容的变化是相关的。 量子态的物理变换由量子信道描述，而量子信道的变换由量子超信道描述。 在本工作中，我们确定了如何逆转或反转量子信道上的物理变换的基本限制，这对于设计和评估量子信息和计算设备至关重要。 特别是，我们在量子超信道的作用下，对量子信道的量子数据处理不等式进行了改进（加强）。 我们识别了一类量子超信道，它似乎是在量子超信道作用下的子单位量子信道的超信道类比，在这种作用下，任意量子信道的熵是非递减的。 我们还提供了在任意量子超信道作用下量子信道熵变的改进不等式。 显示英文摘要

摘要： Quantum information processing and computing tasks can be understood as quantum networks, comprising quantum states and channels and possible physical transformations on them. It is hence pertinent to estimate the change in informational content of quantum processes due to physical transformations they undergo. The physical transformations of quantum states are described by quantum channels, while the transformations of quantum channels are described by quantum superchannels. In this work, we determine fundamental limitations on how well the physical transformation on quantum channels can be undone or reversed, which are of crucial interest to design and benchmark quantum information and computation devices. In particular, we refine (strengthen) the quantum data processing inequality for quantum channels under the action of quantum superchannels. We identify a class of quantum superchannels, which appears to be the superchannel analogue of subunital quantum channels, under the action of which the entropy of an arbitrary quantum channel is nondecreasing. We also provide a refined inequality for the entropy change of quantum channels under the action of an arbitrary quantum superchannel.