Transport properties of vortices in easy flow channels: a Frenkel-Kontorova study

TL;DR

This study investigates vortex transport in easy flow channels, revealing defect-induced low critical currents and a low mobility regime, using molecular dynamics and Frenkel-Kontorova models, with implications for artificial vortex channels.

Contribution

It introduces an analytical approach to defect dynamics in vortex channels and compares simulation results with the Frenkel-Kontorova model, advancing understanding of vortex flow behavior.

Findings

Defects cause near-zero critical current in vortex channels.

A low mobility regime exists at small drives due to defect motion.

Analytical treatment of a single defective vortex row is provided.

Abstract

Incommensurate easy flow channels in an otherwise perfect vortex lattice are investigated. The associated (point) defects in the lattice inside the channel cause an almost vanishing critical current, as shown by molecular dynamics simulations and a comparison with the Frenkel-Kontorova model. In addition to the normal flux flow behavior we find a low mobility regime at small drives associated with defect motion. We treat this situation analytically for the case of a single defective vortex row. We also briefly discuss the relation to existing experiments on artificial vortex channels.