论文标题
动力过渡以易于踢的紧密结合模型
Dynamical transitions in aperiodically kicked tight-binding models
论文作者
论文摘要
如果在具有结构性临时性的紧密结合模型中的局部量子状态会发生嘈杂的进化，那么通常期望它会导致扩散和离域化。在这项工作中，结果表明，踢aubry-andré-harper（aah）模型的本地化阶段对嘈杂进化的效果很强，只要每个时间段就可以交付一次踢球。但是，如果通过随机缺失的踢脚施加强烈的嘈杂扰动，则观察到从初始时间到较长时间的扩散生长阶段的急剧动力过渡。即使在翻译不变的模型中也可以看到这样的急剧过渡。这些转变与扁平频段的存在有关，使用2波段模型，我们为这些观测值获得了分析支持。长时间的扩散演化具有与随机行走相似的机制。急剧过渡发生的时间尺度与噪声的特征有关。值得注意的是，与噪声参数相比，波袋的演化尺度。此外，使用“硬币折腾”调制的踢序序列，据认为噪声中的相关性对于观察到的尖锐跃迁至关重要。
If a localized quantum state in a tight-binding model with structural aperiodicity is subject to noisy evolution, then it is generally expected to result in diffusion and delocalization. In this work, it is shown that the localized phase of the kicked Aubry-André-Harper (AAH) model is robust to the effects of noisy evolution, for long times, provided that some kick is delivered once every time period. However, if strong noisy perturbations are applied by randomly missing kicks, a sharp dynamical transition from a ballistic growth phase at initial times to a diffusive growth phase for longer times is observed. Such sharp transitions are seen even in translationally invariant models. These transitions are related to the existence of flat bands, and using a 2-band model we obtain analytical support for these observations. The diffusive evolution at long times has a mechanism similar to that of a random walk. The time scale at which the sharp transition takes place is related to the characteristics of noise. Remarkably, the wavepacket evolution scales with the noise parameters. Further, using kick sequence modulated by a 'coin toss', it is argued that the correlations in the noise are crucial to the observed sharp transitions.
