Strong field-matching effects in superconducting YBa_ {2} Cu_ {3} O_ {7− δ} films with vortex energy landscapes engineered via masked ion irradiation

Physical review. B, Condensed matter (Impact Factor: 3.66). 11/2011; 85(22). DOI: 10.1103/PhysRevB.85.224502
Source: arXiv

ABSTRACT We have developed a masked ion irradiation technique to engineer the energy landscape for vortices in oxide superconductors. This approach associates the possibility to design the landscape geometry at the nanoscale with the unique capability to adjust the depth of the energy wells for vortices. This enabled us to unveil the key role of vortex channeling in modulating the amplitude of the field matching effects with the artificial energy landscape, and to make the latter govern flux dynamics over an unusually wide range of temperatures and applied fields for high-temperature superconducting films.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We numerically study vortex ordering and pinning in Archimedean tiling substrates composed of square and triangular plaquettes. The two different plaquettes become occupied at different vortex densities, producing commensurate peaks in the magnetization at non-integer matching fields. We find that as the field increases, in some cases the fraction of occupied pins can decrease due to the competition between fillings of the different plaquette types. We also identify a number of different types of vortex orderings as function of field at integer and non-integer commensurate fillings.
    Superconductor Science and Technology 08/2013; 27(7). · 2.80 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We examine the current driven dynamics for vortices interacting with conformal crystal pinning arrays and compare to the dynamics of vortices driven over random pinning arrays. We find that the pinning is enhanced in the conformal arrays over a wide range of fields, consistent with previous results from flux gradient-driven simulations. At fields above this range, the effectiveness of the pinning in the moving vortex state can be enhanced in the random arrays compared to the conformal arrays, leading to crossing of the velocity-force curves.
    Physica C Superconductivity 12/2013; · 1.11 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We study the general problem of a manifold of interacting elastic lines whose spatial correlations are strongly affected by the competition between random and ordered pinning. This is done through magneto-transport experiments with YBa2Cu3O7-d thin films that contain a periodic vortex pinning array created via masked ion irradiation, in addition to the native random pinning. The strong field-matching effects we observe suggest the prevalence of periodic pinning, and indicate that at the matching field each vortex line is bound to an artificial pinning site. However, the vortex-glass transition dimensionality, quasi-2D instead of the usual 3D, evidences reduced vortex-glass correlations along the vortex line. This is also supported by an unusual angular dependence of the magneto-resistance, which greatly differs from that of Bose-glass systems. A quantitative analysis of the angular magnetoresistance allows us to link this behaviour to the enhancement of the system anisotropy, a collateral effect of the ion irradiation.
    New Journal of Physics 10/2013; 15(10). · 3.67 Impact Factor

Full-text (2 Sources)

Available from
May 21, 2014