Eur. Phys. J. Special Topics 187, 145-156 (2010)
https://doi.org/10.1140/epjst/e2010-01279-x

Regular Article

Avalanches in a nonlinear oscillator chain in a periodic potential

Department of Mathematics, University of Portsmouth, Portsmouth PO1 3HF, UK

^a e-mail: dirk.hennig@port.ac.uk

Received: 3 August 2010
Revised: 9 August 2010
Published online: 1 October 2010

Abstract

We consider the dynamics of a chain of coupled units evolving in a periodic substrate potential. The chain is initially in a flat state and situated in a potential well. A bias force, acting as a weak driving mechanism, is applied at a single unit of the chain. We study the instigation of directed transport in two types of system: (i) a microcanonical situation associated with deterministic and conservative dynamics and (ii) the Langevin dynamics when the system is in contact with a heat bath. Interestingly, for the deterministic and conservative dynamics the directed transport is drastically enhanced compared with its Langevin counterpart. In particular, in the deterministic and conservative regime a self-organised redistribution of energy triggers huge-sized avalanches yielding ultimately accelerated transport of the chain. In contrast, in the thermally-assisted process between avalanches the chain settles always into a pinned metastable state impeding continual accelerated chain motion.