Field-enhanced critical parameters in magnetically nanostructured superconductors
Abstract
Within the phenomenological Ginzburg-Landau theory, we demonstrate the enhancement of superconductivity in a superconducting film, when nanostructured by a lattice of magnetic particles. Arrays of out-of-plane magnetized dots (MDs) extend the critical magnetic field and critical current the sample can sustain, due to the interaction of the vortex-antivortex pairs and surrounding supercurrents induced by the dots and the external flux lines. Depending on the stability of the vortex-antivortex lattice, a peak in the Hext-T boundary is found for applied integer and rational matching fields, which agrees with recent experiments [Lange et al., Phys. Rev. Lett. 90, 197006 (2003)]. Due to compensation of MDs- and Hext-induced currents, we predict the field-shifted jc-Hext characteristics, as was actually realized in previous experiment but not commented on [Morgan and Ketterson, Phys. Rev. Lett. 80, 3614 (1998)].
Cite
@article{arxiv.cond-mat/0504645,
title = {Field-enhanced critical parameters in magnetically nanostructured superconductors},
author = {M. V. Milosevic and F. M. Peeters},
journal= {arXiv preprint arXiv:cond-mat/0504645},
year = {2009}
}
Comments
8 pages, 5 figures, to appear in Europhysics Letters