论文标题
鞍点不加热
Saddle-point scrambling without thermalisation
论文作者
论文摘要
事实证明，耗阶级相关器（OTOC）是研究量子系统中热量的有用工具。特别是，尽管集成系统中的马鞍点也可以促进耳ot的快速增长，但有时将OTOC或争夺的指数增长有时被视为量子系统中混乱的指标。通过分析DICKE模型和驱动的Bose-Hubbard二聚体，我们证明了由混乱驱动的OTOC生长可以与长期行为通过鞍点驱动的那样区分。除了长期平均值的定量差异外，马鞍点还会引起混乱的情况下未观察到的大振荡。纠缠熵也强调了这些差异，在混沌驱动的二聚体中与页面曲线预测匹配。这些结果说明了其他标记，可用于区分量子系统中的混沌行为，超出了OTOC的初始指数生长。
Out-of-time-order correlators (OTOCs) have proven to be a useful tool for studying thermalisation in quantum systems. In particular, the exponential growth of OTOCS, or scrambling, is sometimes taken as an indicator of chaos in quantum systems, despite the fact that saddle points in integrable systems can also drive rapid growth in OTOCs. By analysing the Dicke model and a driven Bose-Hubbard dimer, we demonstrate that the OTOC growth driven by chaos can, nonetheless, be distinguished from that driven by saddle points through the long-term behaviour. Besides quantitative differences in the long-term average, the saddle point gives rise to large oscillations not observed in the chaotic case. The differences are also highlighted by entanglement entropy, which in the chaotic driven dimer matches a Page curve prediction. These results illustrate additional markers that can be used to distinguish chaotic behaviour in quantum systems, beyond the initial exponential growth in OTOCs.
