论文标题
部分可观测时空混沌系统的无模型预测
Non-linear fluctuating hydrodynamics for KPZ scaling in isotropic spin chains
论文作者
论文摘要
可众所周知，在可集成的各向同性旋转链中的有限温度自旋传输是超级延伸的，动态自旋相关的猜想始于Kardar-Parisi-Zhang（KPZ）通用类。但是，可集成的自旋链具有时间反转和奇偶校验对称性，而KPZ/随机汉堡方程不存在，它们迫使高阶自旋波动偏离标准的KPZ预测。我们提出了一个非线性波动的流体动力学理论，该理论由两种耦合随机模式组成：局部自旋磁化及其有效速度。我们的理论充分解释了各向同性链中异常自旋动力学的出现：它可以预测自旋结构因子的kPz缩放，但具有对称的准高斯，自旋波动的分布。我们使用矩阵 - 产品状态计算来证实结果。
Finite temperature spin transport in integrable isotropic spin chains is known to be superdiffusive, with dynamical spin correlations that are conjectured to fall into the Kardar-Parisi-Zhang (KPZ) universality class. However, integrable spin chains have time-reversal and parity symmetries that are absent from the KPZ/stochastic Burgers equation, which force higher-order spin fluctuations to deviate from standard KPZ predictions. We put forward a non-linear fluctuating hydrodynamic theory consisting of two coupled stochastic modes: the local spin magnetization and its effective velocity. Our theory fully explains the emergence of anomalous spin dynamics in isotropic chains: it predicts KPZ scaling for the spin structure factor but with a symmetric, quasi-Gaussian, distribution of spin fluctuations. We substantiate our results using matrix-product states calculations.
