Energy Current Cumulants in One-Dimensional Systems in Equilibrium

Abhishek Dhar, Keiji Saitou, Anjan Roy

Research output: Contribution to journalArticle

Abstract

A recent theory based on fluctuating hydrodynamics predicts that one-dimensional interacting systems with particle, momentum, and energy conservation exhibit anomalous transport that falls into two main universality classes. The classification is based on behavior of equilibrium dynamical correlations of the conserved quantities. One class is characterized by sound modes with Kardar-Parisi-Zhang scaling, while the second class has diffusive sound modes. The heat mode follows Lévy statistics, with different exponents for the two classes. Here we consider heat current fluctuations in two specific systems, which are expected to be in the above two universality classes, namely, a hard particle gas with Hamiltonian dynamics and a harmonic chain with momentum conserving stochastic dynamics. Numerical simulations show completely different system-size dependence of current cumulants in these two systems. We explain this numerical observation using a phenomenological model of Lévy walkers with inputs from fluctuating hydrodynamics. This consistently explains the system-size dependence of heat current fluctuations. For the latter system, we derive the cumulant-generating function from a more microscopic theory, which also gives the same system-size dependence of cumulants.

Original languageEnglish
Article number220603
JournalPhysical Review Letters
Volume120
Issue number22
DOIs
Publication statusPublished - 2018 May 31

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heat
conservation
hydrodynamics
energy
momentum
acoustics
energy conservation
statistics
exponents
harmonics
scaling
gases
simulation

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Energy Current Cumulants in One-Dimensional Systems in Equilibrium. / Dhar, Abhishek; Saitou, Keiji; Roy, Anjan.

In: Physical Review Letters, Vol. 120, No. 22, 220603, 31.05.2018.

Research output: Contribution to journalArticle

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