Hybrid Magnetic-Superconducting Nanostructures

IVAN K. SCHULLER, Y. J. ROSEN, J. VILLEGAS, D. PEREZ DE LARA, E. M. GONZALEZ, C. CHILIOTTE, G. PASQUINI, V. BEKERIS AND J. L. VICENT

Vancouver

Congreso; INTERMAG 2012; 2012

IEEE Magnetics Society

Physics in confined geometries is one of the most active areas of research in Solid State and Materials Physics. The extensive activity in this field is driven by the fact that physical length scales are close to structural sizes, which can be controlled using modern thin film and lithography techniques. In addition, a number of applications in the areas of information storage and sensors have moved basic research results into the application area in a very short period of time. A particularly interesting and promising area of research is when two dissimilar materials are in physical proximity ("hybrids") and when simultaneously they are nanostructured at a length scale comparable to interesting physical length scales. We have discovered a variety of exciting and novel results when magnetic and/or superconducting materials are confined into small dimensions and are in close physical proximity. Superconducting pinning in thin superconducting films can be manipulated by the presence of arrays of magnetic and normal nanostructures and be controlled by the magnetic state of the arrays. These serve as model systems for studies of order-disorder and collective pinning in the vortex lattice of superconductors. Interesting effects are observed when the dimensions and distances of the nanostructures are comparable to magnetic length scales such as dipolar, exchange, and domain sizes and superconducting length scales such as the penetration and coherence lengths. Examples of interesting and unusual phenomena which can be engineered into hybrid devices include; magnetic vortices, bistable superconductivity, fractal behavior, and ratchet effects. We have engineered examples of geometrically and magnetically induced effects which otherwise do not exist in either of the individual components of the hybrid and which are representative of the physical phenomena mentioned above.