An analysis of anomalous particle flow between two correlated systems

TL;DR

This paper investigates how correlations between two thermal systems influence the direction of particle flow, revealing that increased correlation can reverse the expected flow from high to low chemical potential.

Contribution

It demonstrates that particle flow direction depends on correlation levels, challenging the traditional view that it is solely determined by chemical potential differences.

Findings

Particle flow can reverse when correlation decreases.

Increased correlation tends to align flow with chemical potential gradient.

Flow direction is not fixed by chemical potential difference alone.

Abstract

We study the effect of correlation on the direction of particle exchange between local thermal sub-systems where the total system is isolated. Our focus is the situation where both sub-systems have the same temperature but different chemical potentials to eliminate the effect of energy transfer due to the temperature difference. The analysis is done in two limits; in the short time scale where the final state of each sub-system is close to its initial thermal state and in a longer time scale where each sub-system's final state can be arbitrary. The results indicate that the conventional flow of particles from a higher chemical potential to a lower one occurs when the correlation which is quantified by mutual information increases. In contrast, an anomalous flow of particles in the reverse direction has a chance to happen when the correlation goes down. Our findings show that the direction of the particle exchange cannot be predetermined by the chemical potential difference in the presence of correlation.