Reverse-domain superconductivity in superconductor-ferromagnet hybrids: effect of a vortex-free channel on the symmetry of I-V characteristics

We demonstrate experimentally that the presence of a single domain wall in an underlying ferromagnetic BaFe_{12}O_{19} substrate can induce a considerable asymmetry in the current (I) - voltage (V) characteristics of a superconducting Al bridge. The observed diode-like effect, i.e. polarity-dependent critical current, is associated with the formation of a vortex-free channel inside the superconducting area which increases the total current flowing through the superconducting bridge without dissipation. The vortex-free region appears only for a certain sign of the injected current and for a limited range of the external magnetic field.

[1]  V. Novosad,et al.  Giant conductance anisotropy in magnetically coupled ferromagnet-superconductor-ferromagnet structures. , 2010 .

[2]  V. Moshchalkov,et al.  Planar superconductor/ferromagnet hybrids: Anisotropy of resistivity induced by magnetic templates , 2009, 0905.2590.

[3]  V. V. Moshchalkov,et al.  Nucleation of superconductivity and vortex matter in superconductor–ferromagnet hybrids , 2009, 0902.1630.

[4]  W. Kwok,et al.  Soft magnetic lithography and giant magnetoresistance in superconducting/ferromagnetic hybrids , 2008 .

[5]  I. Schuller,et al.  Superconducting vortex pinning with artificial magnetic nanostructures , 2008 .

[6]  V. Novosad,et al.  Tunable transport in magnetically coupled MoGe/Permalloy hybrids , 2008 .

[7]  W. Kwok,et al.  Guiding superconducting vortices with magnetic domain walls , 2007, 0705.0555.

[8]  D. Koelle,et al.  Local observation of reverse-domain superconductivity in a superconductor-ferromagnet hybrid. , 2006, Physical review letters.

[9]  V. Moshchalkov,et al.  Effect of reversed magnetic domains on superconductivity in Pb∕BaFe12O19 hybrids , 2006 .

[10]  A. Buzdin,et al.  Proximity effect in superconductor-ferromagnet heterostructures , 2005, cond-mat/0505583.

[11]  S. A. Gusev,et al.  Considerable enhancement of the critical current in a superconducting film by a magnetized magnetic strip , 2005, cond-mat/0504229.

[12]  I. Lyuksyutov,et al.  Ferromagnet–superconductor hybrids , 2004, cond-mat/0409137.

[13]  A. Volodin,et al.  Domain-wall superconductivity in superconductor–ferromagnet hybrids , 2004, Nature materials.

[14]  A. Sokolov,et al.  Domain-wall superconductivity in hybrid superconductor-ferromagnet structures , 2003, cond-mat/0305520.

[15]  V. Moshchalkov,et al.  Nanoengineered magnetic-field-induced superconductivity. , 2002, Physical review letters.

[16]  I. Schuller,et al.  Ordered magnetic nanostructures: fabrication and properties , 2003 .

[17]  I.L.Maksimov,et al.  Distribution of the magnetic field and current density in superconducting films of finite thickness , 2000, cond-mat/0001035.

[18]  T. Klapwijk,et al.  Critical pair-breaking current in superconducting aluminum strips far below T/sub c/ , 1982 .