Europhys. Lett.
Volume 74, Number 2, April 2006
Page(s) 334 - 340
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 22 March 2006
Europhys. Lett., 74 (2), pp. 334-340 (2006)
DOI: 10.1209/epl/i2005-10534-y

Magnetic dipole-vortex interaction in a bilayered superconductor/soft-magnet heterostructure

S. V. Yampolskii, G. I. Yampolskaya and H. Rauh

Institut für Materialwissenschaft, Technische Universität Darmstadt 64287 Darmstadt, Germany

received 5 December 2005; accepted in final form 23 February 2006
published online 22 March 2006

The penetration of the magnetic field of an infinitesimal magnetic dipole into a bilayered type-II superconductor/soft-magnet heterostructure is studied on the basis of the classical London approach. The energies associated with the presence of a straight magnetic vortex in the superconductor layer are derived and the critical dipole moment for the first vortex appearance is obtained when the magnetic dipole faces the superconductor or the soft-magnet constituent. This shows that the presence of the latter constituent can lead to an improvement of the superconducting properties of the heterostructure by either inhibiting vortex penetration into the superconductor constituent or enhancing vortex pinning in the superconductor constituent.

74.78.-w - Superconducting films and low-dimensional structures.
74.25.Op - Mixed states, critical fields, and surface sheaths.

© EDP Sciences 2006