The quantum walk (QW) has proven to be a valuable testbed for fundamental inquiries in quantum technology applications such as quantum simulation and quantum search algorithms. Many benefits have been found by exploring implementations of QWs in various physical systems, including photonic platforms. Here, we propose a platform to perform quantum walks based on ultrafast time-bin encoding (UTBE) and all-optical Kerr gating. This platform supports the scalability of quantum walks to a large number of steps and walkers while retaining a significant degree of programmability. More importantly, ultrafast time bins are encoded at the picosecond time scale, far away from mechanical fluctuations. This enables the scalability of our platform to many modes while preserving excellent interferometric phase stability over extremely long periods of time without requiring active phase stabilization. Our 18-step QW is shown to preserve interferometric phase stability over a period of 50 h, with an overall walk fidelity maintained above 95%.

中文翻译：

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具有超快时间仓编码的光子量子行走


量子行走（QW）已被证明是量子技术应用（例如量子模拟和量子搜索算法）中基本查询的有价值的测试平台。通过探索 QW 在各种物理系统（包括光子平台）中的实现，我们发现了许多好处。在这里，我们提出了一个基于超快时间仓编码（UTBE）和全光克尔门控执行量子行走的平台。该平台支持将量子行走扩展到大量步数和行走器，同时保留很大程度的可编程性。更重要的是，超快时间段以皮秒时间尺度进行编码，远离机械波动。这使得我们的平台能够扩展到多种模式，同时在极长的时间内保持出色的干涉相位稳定性，而无需主动相位稳定。我们的 18 步 QW 可以在 50 小时内保持干涉相位稳定性，整体行走保真度保持在 95% 以上。