Peter Grünberg coauthored experiments revealing a large dependence of electrical resistance on the relative orientation of magnetic layers. In iron-chromium-iron structures, an antiparallel arrangement of the iron-layer magnetization gave higher electrical resistance than a parallel arrangement. The effect grew in structures containing more magnetic layers and substantially exceeded ordinary anisotropic magnetoresistance. This connects magnetic configuration with electrical readout and helped establish giant magnetoresistance as a basis for magnetic sensing.[ref]
Portrait of Peter Grünberg
. Kuebi = Armin Kübelbeck, 25 February 2008. CC BY-SA 3.0, via Wikimedia Commons. Source. Articles by others on the same topic
Peter Grünberg was a German physicist best known for his discovery of the giant magnetoresistance (GMR) effect, which has had a significant impact on the development of hard disk drives and magnetic sensors. His work in this field earned him the Nobel Prize in Physics in 2007, which he shared with Albert Fert, who independently discovered a similar effect.