English

Thermal depinning and creep in strong pinning theory

Superconductivity 2018-09-19 v4 Statistical Mechanics

Abstract

Pinning and thermal creep determine the response of numerous systems containing superstructures, e.g., vortices in type II superconductors, domain walls in ferroics, or dislocations in metals. The combination of drive and thermal fluctuations lead to the superstructure's depinning and its velocity vv determines the electric, magnetic, or mechanical response. It is commonly believed that pinning and creep collapse above the critical drive FcF_c, entailing a sharp rise in the velocity vv. We challenge this perception by studying the effects of thermal fluctuations within the framework of strong vortex pinning in type-II superconductors. In fact, we show that pinning and thermal creep persist far beyond the critical force. The resulting force-velocity characteristic largely maintains its zero-temperature shape and thermal creep manifests itself by a downward renormalisation of the critical drive. Such characteristics is in agreement with Coulomb's law of dry friction and has been often observed in experiments.

Keywords

Cite

@article{arxiv.1802.00652,
  title  = {Thermal depinning and creep in strong pinning theory},
  author = {Martin Buchacek and Roland Willa and Vadim B. Geshkenbein and Gianni Blatter},
  journal= {arXiv preprint arXiv:1802.00652},
  year   = {2018}
}