标题： 弱非可积单位映射中的预热化观测 显示英文标题

标题： Observation of prethermalization in weakly nonintegrable unitary maps

摘要： 我们通过研究接近可积性时单位电路映射的时间依赖最大李雅普诺夫指数$\Lambda(t)$的统计特性来研究预热化。 我们跟踪不同初始条件的轨迹演化，并计算$\Lambda(t)$的均值$\mu(t)$和标准差$\sigma(t)$。 热化意味着在$\mu$的收敛有限值处时间衰减$\sigma \sim t^{-1/2}$。 我们报告了预热化平台，这些平台持续很长时间，其中$\mu$和$\sigma$看起来似乎已收敛到有限值，这似乎意味着不同轨迹具有不同的饱和李雅普诺夫指数值。这种平台的寿命提供了一个新的时间尺度，用于描述接近可积性的多体系统的热化动力学。我们还发现，经过足够长的时间后，平台会收敛到各自对应的热平衡值。 显示英文摘要

摘要： We investigate prethermalization by studying the statistical properties of the time-dependent largest Lyapunov exponent $\Lambda(t)$ for unitary-circuit maps upon approaching integrability. We follow the evolution of trajectories for different initial conditions and compute the mean $\mu(t)$ and standard deviation $\sigma(t)$ of $\Lambda(t)$. Thermalization implies a temporal decay $\sigma \sim t^{-1/2}$ at a converged finite value of $\mu$. We report prethermalization plateaus that persist for long times where both $\mu$ and $\sigma$ appear to have converged to finite values, seemingly implying differing saturated Lyapunov exponent values for different trajectories. The lifetime of such plateaus furnishes a novel time scale characterizing the thermalization dynamics of many-body systems close to integrability. We also find that the plateaus converge to their respective thermal values for long enough times.