English

Elliptic Annular Josephson Tunnel Junctions in an external magnetic field: The statics

Superconductivity 2015-11-05 v1

Abstract

We have investigated the static properties of one-dimensional planar Josephson tunnel junctions in the most general case of elliptic annuli. We have analyzed the dependence of the critical current in the presence of an external magnetic field applied either in the junction plane or in the perpendicular direction. We report a detailed study of both short and long elliptic annular junctions having different eccentricities. For junctions having a normalized perimeter less than one the threshold curves are derived and computed even in the case with one trapped Josephson vortex. For longer junctions a numerical analysis is carried out after the derivation of the appropriate Perturbed sine-Gordon Equation. For a given applied field we find that a number of different phase profiles exist which differ according to the number of fluxon-antifluxon pairs. We demonstrate that in samples made by specularly symmetric electrodes a transverse magnetic field is equivalent to an in-plane field applied in the direction of the current flow. Varying the ellipse eccentricity we reproduce all known results for linear and ring-shaped Josephson tunnel junctions. Experimental data on high-quality Nb/Al-AlOx/Nb elliptic annular junctions support the theoretical analysis provided self-field effects are taken into account.

Keywords

Cite

@article{arxiv.1501.03335,
  title  = {Elliptic Annular Josephson Tunnel Junctions in an external magnetic field: The statics},
  author = {Roberto Monaco and Carmine Granata and Antonio Vettoliere and Jesper Mygind},
  journal= {arXiv preprint arXiv:1501.03335},
  year   = {2015}
}

Comments

30 pages, 13 figures