Secretary General Gunnar Öquist made the announcement: “The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for the year 2007 jointly to Professor Albert Fert of Université Paris–Sud in France and Professor Peter Grünberg of Forschungszentrum in Jülich, Germany.”
Fert and Grünberg discovered giant magnetoresistance independently. In 1988, they and their collaborators made thin, multilayer structures of ferromagnetic iron and chromium. When the researchers applied a magnetic field, the structures’ electrical resistance fell. In Fert’s 30-layer structure, the drop at 4.2 K was 50%. 1 He dubbed the new magnetoresistive effect “giant.”
Grünberg saw a more modest drop of 1.5% in his three-layer structure, but at room temperature. 2 He grasped the effect’s potential for sensing magnetic fields and promptly filed a patent. Within a decade, thanks mostly to R&D at IBM’s Almaden Research Center, tiny GMR-based sensors were reading data in magnetic disk...
