Multi-particle collision simulations of 2D one-component plasmas: anomalous transport and dimensional crossovers

TL;DR

This study uses hybrid multi-particle collision simulations to explore energy and density correlation scaling in 2D and quasi-1D plasmas, revealing that 1D hydrodynamics predictions extend to more extended 2D systems and highlighting the impact of electrostatic fluctuations on anomalous transport.

Contribution

It demonstrates the applicability of 1D nonlinear fluctuating hydrodynamics to 2D plasmas and clarifies the role of electrostatic fluctuations in transport anomalies.

Findings

Nonlinear Fluctuating Hydrodynamics predictions hold in 2D systems with extended dimensions.

Neglecting electrostatic fluctuations overestimates the frequency range of anomalous transport.

Violations of expected scaling hinder observation of asymptotic behavior.

Abstract

By means of hybrid multi-particle collsion--particle-in-cell (MPC-PIC) simulations we study the dynamical scaling of energy and density correlations at equilibrium in moderately coupled 2D and quasi 1D plasmas. We find that the predictions of Nonlinear Fluctuating Hydrodynamics for the structure factors of density and energy fluctuations in 1D systems with three global conservation laws hold true also for two dimensional systems that are more extended along one of the two spatial dimensions. Moreover, from the analysis of the equilibrium energy correlators and density structure factors of both 1D and 2D neutral plasmas, we find that neglecting the contribution of the fluctuations of the vanishing self-consistent electrostatic fields overestimates the interval of frequencies over which the anomalous transport is observed. Such violations of the expected scaling in the currents correlation are found in different regimes, hindering the observation of the asymptotic scaling predicted by the theory.