José María De Teresa
José M. De Teresa finished his Ph.D. thesis in 1997 on colossal magnetoresistance under the supervision of Prof. M. R. Ibarra in the Department of Condensed Matter Physics at the University of Zaragoza (Spain). During the period 1998–2000, he developed a European-funded Madame Curie project under the supervision of Nobel Laureate, Prof. A. Fert, in Orsay, France, where he studied the role of interfaces in magnetic tunnel junctions. Since 2001 he has held a permanent position in CSIC (the Spanish Council of Research) at the Institute of Materials Science of Aragon and since 2003 has also collaborated tightly with the Institute of Nanoscience of Aragon. His current research focus is on the anomalous Hall effect, atomic-size magnetic constrictions, magnetic tunnel junctions, spin-filtering effects, and nanoscale superconducting and magnetic materials created with focused-beam techniques.
Using a double spin-filter tunnel junction consisting of two magnetic insulating layers, researchers have observed a sizeable magnetoresistance without using magnetic electrodes, thus tuning the tunneling via the magnetic state of the insulating layers and by application of an electric voltage.