Nobel Prize In Physics Goes To Hard Drive Enhancers

Nobel Prize  in physics this year has been awarded to researchers whose discovery helps to produce faster and more compact hard drives.

The discovery has helped improve data storage density by at least an order of magnitude. And it is paving the way for several experimental technologies that could increase it even more.

Albert Fert, scientific director at Unité Mixte de Physique CNRS-Thales in France, and Peter Grünberg, recently retired as a research scientist at the Research Centre Jülich in Germany, independently discovered the property, which Fert called giant magnetoresistance (GMR), in 1988. GMR makes it possible to pack far more information onto a hard disk by significantly increasing the sensitivity of detectors used to read bits of information. Within 10 years of its discovery, hard drives based on the effect were commercialized by IBM.

Before GMR was discovered, hard drives depended on a phenomenon called magnetoresistance, which had been understood for well over 100 years. In magnetoresistance, a magnetic field alters the electrical resistance in a material, causing measurable changes in electrical current. In hard drives, this property was used to detect bits of information--regions on a disk that have magnetized in one of two directions. As the head passes over such a region, its magnetic field changes a current flowing in the head, registering a 1 or a 0. But the technology ran into problems as the density of memory increased and researchers developed ways to write ever smaller bits. "Conventional sensors were finding it harder and harder to detect the magnetic bits stored on a hard drive," says David Awschalom, a professor of physics at the University of California Santa Barbara. "The industry was facing this brick wall. How do you put more information on a disk and still read it?"