What is GMR?
Giant Magneto Resistance is the phenomenon behind the technology used by the read heads in modern drives to read the data stored on disk platters. The GMR effect is a property of thin films of certain materials that experience large changes in resistance as a result of very small changes in magnetic field. This effect allows the information about changes in magnetic fields to be deciphered by detecting changes in resistance. And since even minute changes in magnetic field can be detected, these magnetised spots can be more closely packed, leading to greater storage area on a platter of the same size. The 2007 Nobel Prize for Physics was awarded to the discoverers of this effect—Albert Fert and Peter Grünberg.