From stochastic spin chains to quantum Kardar-Parisi-Zhang dynamics

从Kardar-Parisi-Zhang缩放到约瑟夫森结阵列中的孤子繁衍

From Kardar-Parisi-Zhang scaling to soliton proliferation in Josephson junction arrays

研究利用约瑟夫森结阵列观察KPZ缩放定律及孤子繁衍现象，通过数值模拟和分析论证揭示非平衡系统的时间演化特性。

Kardar-Parisi-Zhang physics in the quantum Heisenberg magnet

Equilibrium spatio-temporal correlation functions are central to understanding weak nonequilibrium physics. In certain local one-dimensional classical systems with three conservation laws they show universal features. Namely, fluctuations around ballistically propagating sound modes can be described by the celebrated Kardar-Parisi-Zhang (KPZ) universality class. Can such universality class be found also in quantum systems? By unambiguously demonstrating that the KPZ scaling function describes magnetization dynamics in the SU(2) symmetric Heisenberg spin chain we show, for the first time, that …

Quantum gas microscopy of Kardar-Parisi-Zhang superdiffusion

The Kardar-Parisi-Zhang (KPZ) universality class describes the coarse-grained behavior of a wealth of classical stochastic models. Surprisingly, it was recently conjectured to also describe spin transport in the one-dimensional quantum Heisenberg model. We test this conjecture by experimentally probing transport in a cold-atom quantum simulator via the relaxation of domain walls in spin chains of up to 50 spins. We find that domain-wall relaxation is indeed governed by the KPZ dynamical exponent $z = 3/2$, and that the occurrence of KPZ scaling requires both integrability and a non-abelian SU(…

Universal Kardar-Parisi-Zhang dynamics in integrable quantum systems

Although the Bethe ansatz solution of the spin-1/2 Heisenberg model dates back nearly a century, the anomalous nature of its high-temperature transport dynamics has only recently been uncovered. Indeed, numerical and experimental observations have demonstrated that spin transport in this paradigmatic model falls into the Kardar-Parisi-Zhang (KPZ) universality class. This has inspired the significantly stronger conjecture that KPZ dynamics, in fact, occur in all integrable spin chains with non-Abelian symmetry. Here, we provide extensive numerical evidence affirming this conjecture. Moreover, w…

数字量子模拟器上Kardar-Parisi-Zhang标度的证据

Evidence of Kardar-Parisi-Zhang scaling on a digital quantum simulator

本研究在含噪近期量子器件上模拟自旋1/2 XXZ自旋链的量子动力学，提取到与KPZ标度一致的超扩散指数，并验证了可积性破缺势下自旋扩散的恢复，为非平衡统计力学的流体动力学涌现研究提供量子模拟证据。

Anomalous ballistic scaling in the tensionless or inviscid Kardar-Parisi-Zhang equation

The one-dimensional Kardar-Parisi-Zhang (KPZ) equation is becoming an overarching paradigm for the scaling of nonequilibrium, spatially extended, classical and quantum systems with strong correlations. Recent analytical solutions have uncovered a rich structure regarding its scaling exponents and fluctuation statistics. However, the zero surface tension or zero viscosity case eludes such analytical solutions and has remained ill-understood. Using numerical simulations, we elucidate a well-defined universality class for this case that differs from that of the viscous case, featuring intrinsical…