Long-Range Correlations under Temperature Gradients: A Molecular Dynamics Study of Simple Fluids

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Nakano, Hiroyoshi, Yokota, Kazuma
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929760995639296
author Nakano, Hiroyoshi
Yokota, Kazuma
author_facet Nakano, Hiroyoshi
Yokota, Kazuma
contents In fluids under temperature gradients, long-range correlations (LRCs) emerge generically, leading to enhanced density fluctuations. This phenomenon, characterized by the $\boldsymbol{q}^{-4}$ divergence in the static structure factor (where $\boldsymbol{q}$ is the wavenumber), has been extensively studied both theoretically and experimentally. However, they remain unexplored in Hamiltonian particle systems using molecular dynamics (MD) simulations. This Letter reports the first MD study to provide unambiguous observations of the LRCs. We demonstrate this by three distinct approaches: (1) measuring the static structure factor and directly observing the $\boldsymbol{q}^{-4}$ divergence characterizing the LRCs; (2) detecting the corresponding $\boldsymbol{q}^{-4}$ divergence in the dynamic structure factor; (3) establishing a quantitative agreement between MD results and predictions from fluctuating hydrodynamics, the phenomenological theory that predicts the LRCs. Our findings demonstrate that MD simulations offer a powerful complementary tool to theoretical and experimental investigations of LRCs.
format Preprint
id arxiv_https___arxiv_org_abs_2411_04416
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Long-Range Correlations under Temperature Gradients: A Molecular Dynamics Study of Simple Fluids
Nakano, Hiroyoshi
Yokota, Kazuma
Statistical Mechanics
Soft Condensed Matter
In fluids under temperature gradients, long-range correlations (LRCs) emerge generically, leading to enhanced density fluctuations. This phenomenon, characterized by the $\boldsymbol{q}^{-4}$ divergence in the static structure factor (where $\boldsymbol{q}$ is the wavenumber), has been extensively studied both theoretically and experimentally. However, they remain unexplored in Hamiltonian particle systems using molecular dynamics (MD) simulations. This Letter reports the first MD study to provide unambiguous observations of the LRCs. We demonstrate this by three distinct approaches: (1) measuring the static structure factor and directly observing the $\boldsymbol{q}^{-4}$ divergence characterizing the LRCs; (2) detecting the corresponding $\boldsymbol{q}^{-4}$ divergence in the dynamic structure factor; (3) establishing a quantitative agreement between MD results and predictions from fluctuating hydrodynamics, the phenomenological theory that predicts the LRCs. Our findings demonstrate that MD simulations offer a powerful complementary tool to theoretical and experimental investigations of LRCs.
title Long-Range Correlations under Temperature Gradients: A Molecular Dynamics Study of Simple Fluids
topic Statistical Mechanics
Soft Condensed Matter
url https://arxiv.org/abs/2411.04416