论文标题
来自量子旋转链中新兴的古典孤子的超延伸
Superdiffusion from emergent classical solitons in quantum spin chains
论文作者
论文摘要
已知量子海森堡旋转链中的有限温度自旋传输是超级延伸的，并且已经猜想位于Kardar-Parisi-Zhang（KPZ）通用类中。使用动力学传输理论，我们直接通过微观监视来计算海森堡链的KPZ耦合强度作为温度的函数。该结果与密度 - 矩阵重新归一化组模拟非常吻合。我们在经典连续的Landau-Lifshitz Ferromagnet中建立了严格的量子古典对应关系。我们得出的结论是，KPZ普遍性在经典和量子整合的各向同性磁体中具有相同的起源：低能经典孤子的有限温度气体。
Finite-temperature spin transport in the quantum Heisenberg spin chain is known to be superdiffusive, and has been conjectured to lie in the Kardar-Parisi-Zhang (KPZ) universality class. Using a kinetic theory of transport, we compute the KPZ coupling strength for the Heisenberg chain as a function of temperature, directly from microscopics; the results agree well with density-matrix renormalization group simulations. We establish a rigorous quantum-classical correspondence between the "giant quasiparticles" that govern superdiffusion and solitons in the classical continuous Landau-Lifshitz ferromagnet. We conclude that KPZ universality has the same origin in classical and quantum integrable isotropic magnets: a finite-temperature gas of low-energy classical solitons.
