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arXiv · 1910.08266

Kardar-Parisi-Zhang universality from soft gauge modes

Vir B. Bulchandani
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Abstract

The emergence of superdiffusive spin dynamics in integrable classical and quantum magnets is well established by now, but there is no generally valid theoretical explanation for this phenomenon. A fundamental difficulty is that the hydrodynamic fluctuations of conserved quasiparticle modes are purely diffusive. We argue that in isotropic integrable magnets, a complete hydrodynamic description must include soft "gauge" degrees of freedom, that arise from spontaneous breaking of the Bethe pseudovacuum symmetry. We show that the coarse-grained time evolution of these modes lies in the Kardar-Parisi-Zhang universality class of dynamics.

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Vir B. Bulchandani. 2020-01-30. Kardar-Parisi-Zhang universality from soft gauge modes. https://doi.org/10.1103/physrevb.101.041411

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