Ordering kinetics in the active Ising model

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Bandyopadhyay, Sayam, Chatterjee, Swarnajit, Dutta, Aditya Kumar, Karmakar, Mintu, Rieger, Heiko, Paul, Raja
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910496559464448
author Bandyopadhyay, Sayam
Chatterjee, Swarnajit
Dutta, Aditya Kumar
Karmakar, Mintu
Rieger, Heiko
Paul, Raja
author_facet Bandyopadhyay, Sayam
Chatterjee, Swarnajit
Dutta, Aditya Kumar
Karmakar, Mintu
Rieger, Heiko
Paul, Raja
contents We undertake a numerical study of the ordering kinetics in the two-dimensional ($2d$) active Ising model (AIM), a discrete flocking model with a conserved density field coupled to a non-conserved magnetization field. We find that for a quench into the liquid-gas coexistence region and in the ordered liquid region, the characteristic length scale of both the density and magnetization domains follows the Lifshitz-Cahn-Allen (LCA) growth law: $R(t) \sim t^{1/2}$, consistent with the growth law of passive systems with scalar order parameter and non-conserved dynamics. The system morphology is analyzed with the two-point correlation function and its Fourier transform, the structure factor, which conforms to the well-known Porod's law, a manifestation of the coarsening of compact domains with smooth boundaries. We also find the domain growth exponent unaffected by different noise strengths and self-propulsion velocities of the active particles. However, transverse diffusion is found to play the most significant role in the growth kinetics of the AIM. We extract the same growth exponent by solving the hydrodynamic equations of the AIM.
format Preprint
id arxiv_https___arxiv_org_abs_2401_13471
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Ordering kinetics in the active Ising model
Bandyopadhyay, Sayam
Chatterjee, Swarnajit
Dutta, Aditya Kumar
Karmakar, Mintu
Rieger, Heiko
Paul, Raja
Statistical Mechanics
We undertake a numerical study of the ordering kinetics in the two-dimensional ($2d$) active Ising model (AIM), a discrete flocking model with a conserved density field coupled to a non-conserved magnetization field. We find that for a quench into the liquid-gas coexistence region and in the ordered liquid region, the characteristic length scale of both the density and magnetization domains follows the Lifshitz-Cahn-Allen (LCA) growth law: $R(t) \sim t^{1/2}$, consistent with the growth law of passive systems with scalar order parameter and non-conserved dynamics. The system morphology is analyzed with the two-point correlation function and its Fourier transform, the structure factor, which conforms to the well-known Porod's law, a manifestation of the coarsening of compact domains with smooth boundaries. We also find the domain growth exponent unaffected by different noise strengths and self-propulsion velocities of the active particles. However, transverse diffusion is found to play the most significant role in the growth kinetics of the AIM. We extract the same growth exponent by solving the hydrodynamic equations of the AIM.
title Ordering kinetics in the active Ising model
topic Statistical Mechanics
url https://arxiv.org/abs/2401.13471