Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Transition from slow Abrikosov to fast moving Josephson vortices in iron pnictide superconductors

Transition from slow Abrikosov to fast moving Josephson vortices in iron pnictide superconductors Iron pnictides are layered high T c superconductors with moderate material anisotropy and thus Abrikosov vortices are expected in the mixed state. Yet, we have discovered a distinct change in the nature of the vortices from Abrikosov-like to Josephson-like in the pnictide superconductor SmFeAs(O,F) with T c~48–50 K on cooling below a temperature T *~41–42 K, despite its moderate electronic anisotropy γ~4–6. This transition is hallmarked by a sharp drop in the critical current and accordingly a jump in the flux-flow voltage in a magnetic field precisely aligned along the FeAs layers, indicative of highly mobile vortices. T * coincides well with the temperature where the coherence length ξ c perpendicular to the layers matches half of the FeAs-layer spacing. For fields slightly out-of-plane (> 0.1°– 0.15°) the vortices are completely immobilized as well-pinned Abrikosov segments are introduced when the vortex crosses the FeAs layers. We interpret these findings as a transition from well-pinned, slow moving Abrikosov vortices at high temperatures to weakly pinned, fast flowing Josephson vortices at low temperatures. This vortex dynamics could become technologically relevant as superconducting applications will always operate deep in the Josephson regime. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Nature Materials Springer Journals

Transition from slow Abrikosov to fast moving Josephson vortices in iron pnictide superconductors

Download PDF
5 pages

Loading next page...
 
/lp/springer-journals/transition-from-slow-abrikosov-to-fast-moving-josephson-vortices-in-1vX490f8uA

References (32)

Publisher
Springer Journals
Copyright
Copyright © 2012 by Nature Publishing Group
Subject
Materials Science; Materials Science, general; Optical and Electronic Materials; Biomaterials; Nanotechnology; Condensed Matter Physics
ISSN
1476-1122
eISSN
1476-4660
DOI
10.1038/nmat3489
Publisher site
See Article on Publisher Site

Abstract

Iron pnictides are layered high T c superconductors with moderate material anisotropy and thus Abrikosov vortices are expected in the mixed state. Yet, we have discovered a distinct change in the nature of the vortices from Abrikosov-like to Josephson-like in the pnictide superconductor SmFeAs(O,F) with T c~48–50 K on cooling below a temperature T *~41–42 K, despite its moderate electronic anisotropy γ~4–6. This transition is hallmarked by a sharp drop in the critical current and accordingly a jump in the flux-flow voltage in a magnetic field precisely aligned along the FeAs layers, indicative of highly mobile vortices. T * coincides well with the temperature where the coherence length ξ c perpendicular to the layers matches half of the FeAs-layer spacing. For fields slightly out-of-plane (> 0.1°– 0.15°) the vortices are completely immobilized as well-pinned Abrikosov segments are introduced when the vortex crosses the FeAs layers. We interpret these findings as a transition from well-pinned, slow moving Abrikosov vortices at high temperatures to weakly pinned, fast flowing Josephson vortices at low temperatures. This vortex dynamics could become technologically relevant as superconducting applications will always operate deep in the Josephson regime.

Journal

Nature Materials – Springer Journals

Published: Nov 25, 2012

There are no references for this article.