Title: From classical to quantum walk via erasure of which-way information Show Chinese title

Title: 通过擦除路径信息从经典漫步到量子漫步

Abstract: Decoherence transforms a ballistic quantum walk into a diffusive classical random walk. After each step the environment measures the particle's path and the outside world gets to know the which-way information. The relation between the which-way information and the classicality of the spatial distribution is clearly visible in the multi-coin quantum walk in which the information about particle's path is encoded in the multi-coin degree of freedom. The more information is stored on the coins, the more classical and diffusive the spatial distribution is. Here, we propose a generalized version of the quantum eraser scenario that allows for complex erasure strategies. We show that the which-way information can be erased from the coins and the ballistic features in the spatial probability distribution can be recovered. Show Chinese abstract

Abstract: 退相干将弹道量子行走转化为扩散的经典随机行走。 每次步骤后，环境测量粒子的路径，外部世界便能知道路径信息。 在多硬币量子行走中，路径信息被编码在多硬币自由度中，路径信息与空间分布的经典性之间的关系显而易见。 硬币上存储的信息越多，空间分布就越经典和扩散。 在这里，我们提出了一种广义的量子擦除场景，允许复杂的擦除策略。 我们证明可以从硬币中擦除路径信息，并可以恢复空间概率分布中的弹道特性。