giant magnetoresistance

Giant magnetoresistance (GMR) is a quantum mechanical effect observed in thin-film materials. It describes an extreme change in electrical resistance within a material when exposed to an applied magnetic field. This phenomenon was independently discovered by Peter Gründberg and Albert Fert, who shared the 2007 Nobel Prize in Physics for their work.12

GMR is achieved by layering magnetic and nonmagnetic metals. The resistance can be significantly altered by changing the direction of magnetization within these layers. This effect has had a profound impact on technology, leading to a dramatic increase in the data storage capacity of devices like computer hard drives.21