Power Spectra of the Total Occupancy in the Totally Asymmetric Simple Exclusion Process

TL;DR

This paper investigates the power spectra of total particle occupancy in the TASEP model, revealing algebraic decay and oscillations in different phases, using simulations and analytic methods to understand non-equilibrium dynamics.

Contribution

It provides a detailed analysis of the power spectrum behavior in TASEP, highlighting phase-dependent decay and oscillations with new analytic insights.

Findings

Power spectrum exhibits algebraic decay with specific exponents in different phases.

Pronounced oscillations occur within high/low density phases, damping into power laws.

Behavior explained by driven biased diffusion with conserved noise.

Abstract

As a solvable and broadly applicable model system, the totally asymmetric exclusion process enjoys iconic status in the theory of non-equilibrium phase transitions. Here, we focus on the time dependence of the total number of particles on a 1-dimensional open lattice, and its power spectrum. Using both Monte Carlo simulations and analytic methods, we explore its behavior in different characteristic regimes. In the maximal current phase and on the coexistence line (between high/low density phases), the power spectrum displays algebraic decay, with exponents -1.62 and -2.00, respectively. Deep within the high/low density phases, we find pronounced \emph{oscillations}, which damp into power laws. This behavior can be understood in terms of driven biased diffusion with conserved noise in the bulk.