Many experimentally relevant quantum spin chains are approximately integrable, and support long-lived quasiparticle excitations. A canonical example of integrable model of quantum magnetism is the XXZ spin chain, for which energy spreads ballistically, but, surprisingly, spin transport can be diffusive or superdiffusive. We review the transport properties of this model using an intuitive quasiparticle picture that relies on the recently introduced framework of generalized hydrodynamics. We discuss how anomalous linear response properties emerge from hierarchies of quasiparticles both in integrable and near-integrable limits, with an emphasis on the role of hydrodynamic fluctuations. We also comment on recent developments including non-linear response, full-counting statistics and far-from-equilibrium transport. We provide an overview of recent numerical and experimental results on transport in XXZ spin chains.

中文翻译：

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相互作用自旋链中热准粒子的反常输运

许多实验相关的量子自旋链是近似可积的，并支持长寿命的准粒子激发。量子磁性可积模型的一个典型例子是 XXZ 自旋链，能量以弹道方式传播，但令人惊讶的是，自旋传输可以是扩散的或超扩散的。我们使用依赖于最近引入的广义流体动力学框架的直观准粒子图片来回顾该模型的传输特性。我们讨论了异常线性响应特性如何从可积和近可积极限的准粒子层级中出现，重点是流体动力学波动的作用。我们还评论了最近的发展，包括非线性响应、全计数统计和远离平衡传输。