Too Close to Integrable: Crossover from Normal to Anomalous Heat Diffusion
| Autor: | Antonio Politi, Stefano Lepri, Roberto Livi |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Conservation law Statistical Mechanics (cond-mat.stat-mech) nonequilibrium statistical physics General Physics and Astronomy FOS: Physical sciences Transport Statistical mechanics Renormalization group Thermal conduction 01 natural sciences Quantum mechanics 0103 physical sciences Quasiparticle Heat equation 010306 general physics Toda lattice Scaling Condensed Matter - Statistical Mechanics |
| Zdroj: | Physical review letters 125 (2020). doi:10.1103/PhysRevLett.125.040604 info:cnr-pdr/source/autori:Lepri, Stefano; Livi, Roberto; Politi, Antonio/titolo:Too Close to Integrable: Crossover from Normal to Anomalous Heat Diffusion/doi:10.1103%2FPhysRevLett.125.040604/rivista:Physical review letters (Print)/anno:2020/pagina_da:/pagina_a:/intervallo_pagine:/volume:125 |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/PhysRevLett.125.040604 |
| Popis: | Energy transport in one-dimensional chains of particles with three conservation laws is generically anomalous and belongs to the Kardar-Parisi-Zhang dynamical universality class. Surprisingly, some examples where an apparent normal heat diffusion is found over a large range of length scales were reported. We propose a novel physical explanation of these intriguing observations. We develop a scaling analysis which explains how this may happen in the vicinity of an integrable limit, such as, but not only, the famous Toda model. In this limit, heat transport is mostly supplied by quasi-particles with a very large mean free path $\ell$. Upon increasing the system size $L$, three different regimes can be observed: a ballistic one, an intermediate diffusive range, and, eventually, the crossover to the anomalous (hydrodynamic) regime. Our theoretical considerations are supported by numerical simulations of a gas of diatomic hard-point particles for almost equal masses and of a weakly perturbed Toda chain. Finally, we discuss the case of the perturbed harmonic chain, which exhibits a yet different scenario. Comment: Published version |
| Databáze: | OpenAIRE |
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