论文标题
使用观测熵见证量子混乱
Witnessing quantum chaos using observational entropy
论文作者
论文摘要
我们研究了量子踢顶（QKT）模型的观察熵（OE），其经典对应物具有不同的阶段：规则，混合或混乱，具体取决于踢踢参数的强度。我们表明，在常规阶段，OE的对数长度超出了临界值，而在混乱状态下，OE的生长速度更快。在动力学中，我们证明了OE的短期增长率是对系统混乱性的量度，并将结果与超时订购的相关器（OTOC）进行了比较。此外，我们表明，在深度量子状态下，与OTOC结果相比，从OE获得的结果更为强大。最后，我们还研究了OE的长期行为，以区分鞍点争夺和真正的混乱，与后者相比，前者显示出巨大的持续波动。
We study observation entropy (OE) for the Quantum kicked top (QKT) model, whose classical counterpart possesses different phases: regular, mixed, or chaotic, depending on the strength of the kicking parameter. We show that OE grows logarithmically with coarse-graining length beyond a critical value in the regular phase, while OE growth is much faster in the chaotic regime. In the dynamics, we demonstrate that the short-time growth rate of OE acts as a measure of the chaoticity in the system, and we compare our results with out-of-time-ordered correlators (OTOC). Moreover, we show that in the deep quantum regime, the results obtained from OE are much more robust compared to OTOC results. Finally, we also investigate the long-time behaviour of OE to distinguish between saddle-point scrambling and true chaos, where the former shows large persistent fluctuations compared to the latter.
