Incommensuration Effects and Dynamics in Vortex Chains

TL;DR

This paper uses numerical simulations to study vortex chain dynamics in a 2D vortex system, revealing incommensuration effects, a two-stage depinning process, and phase locking phenomena.

Contribution

It demonstrates the role of incommensuration in vortex chain motion and uncovers a two-stage depinning mechanism with soliton-like pulses and phase locking under combined drives.

Findings

Incommensuration causes the onset of vortex chain motion.

Depinning occurs in two stages with soliton-like pulses.

Phase locking observed with combined ac and dc drives.

Abstract

We examine the motion of one-dimensional (1D) vortex matter embedded in a 2D vortex system with weak pinning using numerical simulations. We confirm the conjecture of Matsuda et al. [Science 294, 2136 (2001)] that the onset of the temperature induced motion of the chain is due to an incommensuration effect of the chain with the periodic potential created by the bulk vortices. In addition, under an applied driving force we find a two stage depinning transition, where the initial depinning of the vortex chain occurs through soliton like pulses. When an ac drive is added to the dc drive, we observe phase locking of the moving vortex chain.