标题： 量子各向同性自旋链中高阶累积量的普遍标度 显示英文标题

标题： Universal scaling of higher-order cumulants in quantum isotropic spin chains

摘要： 理解在量子多体层面上远离平衡的输运动力学的普遍行为是一个长期存在的挑战。 特别是，对非局域关联函数的普遍动力学的完整表征仍然 largely 未知。 在本信中，我们揭示了一维各向同性海森堡模型中高阶累积量的普遍标度定律，揭示了仅在高阶关联中可访问的非平衡动力学的异常行为。 通过数值模拟和全计数统计，我们确定了不同类型的螺旋和畴壁初始状态下的自旋极化转移和对比累积量的幂律。 基于这些物理状态，我们统一了高阶累积量的标度行为，导致两种类型的动力学：异常扩散和超扩散。 对于前者，这些高阶累积量表现出与高斯统计的偏差，前四阶的标度指数相同。 而对于后者，我们观察到KPZ普适性的破坏，第三和第四阶的指数与前两阶显著不同。 我们的结果也与最近的实验观测一致，推动了对远离平衡输运现象的理解。 显示英文摘要

摘要： Understanding universal behavior of far-from-equilibrium transport dynamics at a quantum many body level is a longstanding challenge. In particular, a full characterization of universal dynamics of nonlocal correlation functions still remains largely unknown. In this letter, we uncover universal scaling laws of higher-order cumulants in one-dimensional isotropic Heisenberg model, revealing anomalous behaviors of nonequilibrium dynamics exclusively accessible in higher-order correlations. By means of numerical simulations and full counting statistics, we determine the power laws of both the spin polarization transfer and contrast cumulants for different kinds of helix and domain-wall initial states. Building on such physical states, we unify the scaling behavior of the higher-order cumulants, giving rise to two types of dynamics: anomalous diffusive and superdiffusive. For the former, these higher cumulants show a deviation from Gaussian statistics, with the scaling exponents being identical for the first four orders. For the latter, however, we observe a breakdown of KPZ universality, with the exponents of the third and fourth orders differing significantly from those of the first two. Our results are also agreeable with recent experimental observations, advancing understanding of far-from-equilibrium transport phenomena.