AI 中文总结
研究通过引入子空间重启协议，以离散时间量子行走为例，利用选择性重置驱动其进入漂移扩散区域，借助惠更斯 - 菲涅耳机制解释现象，确立了子空间重启是控制合成晶格中量子到经典转变的途径。
AI 中文摘要
量子过程的重启通常被建模为全局重新初始化，会抹去系统的整个历史。本文引入子空间重启，这是一种仅定期重置内部自由度同时保留空间分布的协议，作为量子到经典转变的可调旋钮。以离散时间量子行走为例，表明这种选择性重置将行走者驱动到一个设计好的漂移扩散区域。此现象可通过惠更斯 - 菲涅耳机制理解，每次重启将波函数分割成一组独立的次级源以筛选长程相关性并分离出稳健的经典主干，其漂移和扩散率由初始硬币的几何取向和重启周期设定。残余量子干涉局限于有效光锥，仅作为短程修正存在，对这些系数进行重整化并在累积量上留下周期性调制。我们的结果将子空间重启确立为控制合成晶格中量子到经典转变的一条途径。
英文摘要
Restart of a quantum process is typically modeled as a global reinitialization that erases the system's entire history. Here we introduce subspace restart, a protocol that periodically resets only the internal degrees of freedom while preserving the spatial distribution, as a tunable knob for the quantum-to-classical crossover. Using the discrete-time quantum walk as an example, we show that this selective reset drives the walker into an engineered drifted-diffusion regime. This phenomenon can be understood by a Huygens-Fresnel mechanism, where each restart fragments the wave function into a set of independent secondary sources to screen long-range correlations and isolate a robust classical backbone, whose drift and diffusivity are set by the geometric orientation of the initial coin and the restart period. Residual quantum interference, confined to effective light cones, survives only as a short-range correction that renormalizes these coefficients and imprints periodic modulations on the cumulants. Our results establish subspace restart as a route to controlling the quantum-to-classical crossover in synthetic lattices.
Comments7 pages, 4 figures
