The quantum switch, a process enabling a coherent superposition of different orders of quantum channels, has garnered significant attention due to its ability to enable noiseless communications through noisy channels, such as entanglement-breaking channels. However, its practical implementation and scalability remain challenging. In contrast, the spatial superposition of quantum channels is more accessible experimentally and has been shown to enhance channel capacity, although it does not match the performance of the quantum switch. In this work, we present preliminary theoretical results demonstrating that, by applying tools of the quantum random walk framework to the spatial superposition of channels, it is possible to replicate the output of a quantum switch. These findings suggest a promising and more feasible route to emulate the quantum switch, offering both practical advantages and interpretative clarity.

翻译：量子开关作为一种能够实现量子信道不同顺序相干叠加的过程，因其能够通过噪声信道（如纠缠破坏信道）实现无噪声通信而受到广泛关注。然而，其实际实现与可扩展性仍面临挑战。相比之下，量子信道的空间叠加在实验上更易实现，并且已被证明能提升信道容量，尽管其性能尚无法与量子开关匹敌。在本工作中，我们提出了初步的理论结果，表明通过将量子随机行走框架的工具应用于信道的空间叠加，可以复现量子开关的输出。这些发现为模拟量子开关提供了一条前景广阔且更具可行性的途径，兼具实用优势与解释清晰性。