Dimer diffusion in a washboard potential

TL;DR

This paper investigates how a two-particle dimer moves over a periodic potential, revealing complex behaviors in mobility and diffusion influenced by system parameters, through combined numerical and analytical methods.

Contribution

It provides a detailed analysis of dimer transport on a washboard potential, highlighting differences from monomer dynamics and exploring parameter effects.

Findings

Mobility and diffusion are non-monotonic functions of driving force.

Dimer properties depend on equilibrium length, coupling strength, and damping.

Transport characteristics differ significantly from monomer cases.

Abstract

The transport of a dimer, consisting of two Brownian particles bounded by a harmonic potential, moving on a periodic substrate is investigated both numerically and analytically. The mobility and diffusion of the dimer center of mass present distinct properties when compared with those of a monomer under the same transport conditions. Both the average current and the diffusion coefficient are found to be complicated non-monotonic functions of the driving force. The influence of dimer equilibrium length, coupling strength and damping constant on the dimer transport properties are also examined in detail.