Pinning and Sliding of Driven Elastic Systems: from Domain Walls to Charge Density Waves

TL;DR

This review discusses the theory of pinning and sliding phenomena in disordered elastic systems, covering collective and local effects, depinning transitions, thermal and ac effects, and applications to various physical systems.

Contribution

It provides a comprehensive synthesis of the collective and local pinning theories, including new insights into depinning, creep, and the role of topological defects in driven elastic systems.

Findings

Thermal fluctuations smear the depinning transition enabling creep motion.

AC driving replaces sharp depinning with velocity hysteresis.

Local pinning reveals complex energy landscapes and quantum tunneling effects.

Abstract

The review is devoted to the theory of collective and it local pinning effects in various disordered non-linear driven systems. Although the emphasis is put on charge and spin density waves and magnetic domain walls, the theory has also applications to flux lines and lattices thereof, dislocation lines, adsorbed mono-layers and related systems. In the first part we focus on the theory of the collective pinning which includes the equilibrium properties of elastic systems with frozen-in disorder as well as the features close to the dynamic depinning transition enforced by an external driving force and at finite temperatures. Thermal fluctuations smear out this transition and allow for a creep motion of the elastic objects even at small forces. An ac-driving force also destroys the sharp transition which is replaced by a velocity hysteresis. The second part is devoted to the local pinning picture and its applications. Inclusion of plastic deformations results in a rich cross-over behavior of the force-velocity relation as well as of the frequency dependence of the dynamic response. The local pinning recovers and exploits new elements of the energy landscape such as termination points of metastable branches or irreversibility of other ones related to generation of topological defects in the course of sliding. It also gives access to the quantum creep described as a tunneling between retarded and advanced configurations.