Assisted exchange models in one dimension

TL;DR

This paper introduces a one-dimensional assisted exchange model with multiple particle species, revealing complex phenomena like density-dependent current reversal and negative differential mobility, and provides exact analytical results for steady states and correlations.

Contribution

It presents a novel multi-species exchange model with a pair factorized steady state and exact solutions, highlighting complex current behaviors.

Findings

Current exhibits density-dependent reversal

Negative differential mobility observed

Multiple current reversal points in multi-species model

Abstract

We introduce an assisted exchange model (AEM) on a one dimensional periodic lattice with (K+1) different species of hard core particles, where the exchange rate depends on the pair of particles which undergo exchange and their immediate left neighbor. We show that this stochastic process has a pair factorized steady state for a broad class of exchange dynamics. We calculate exactly the particle current and spatial correlations (K+1)-species AEM using a transfer matrix formalism. Interestingly the current in AEM exhibits density dependent current reversal and negative differential mobility- both of which have been discussed elaborately by using a two species exchange model which resembles the partially asymmetric conserved lattice gas model in one dimension. Moreover, multi-species version of AEM exhibits additional features like multiple points of current reversal, and unusual response of particle current.