标题： 维度改变量子通道的凸分解 显示英文标题

标题： Convex decomposition of dimension-altering quantum channels

摘要： 量子通道是完全正且迹保持的映射，可以改变系统的维度；例如，从一个量子比特到一个量子三态的量子通道。 我们研究了改变维度的量子通道的凸集性质，特别是以极端通道的凸组合形式进行通道分解的问题。 我们提供了极端通道和广义极端通道的各种量子电路表示，这些表示可以用于优化以近似分解任意通道。 我们对低维通道进行了数值模拟，以展示我们的通道分解方案。 显示英文摘要

摘要： Quantum channels, which are completely positive and trace preserving mappings, can alter the dimension of a system; e.g., a quantum channel from a qubit to a qutrit. We study the convex set properties of dimension-altering quantum channels, and particularly the channel decomposition problem in terms of convex sum of extreme channels. We provide various quantum circuit representations of extreme and generalized extreme channels, which can be employed in an optimization to approximately decompose an arbitrary channel. Numerical simulations of low-dimensional channels are performed to demonstrate our channel decomposition scheme.