British physicist Stuart Parkin awarded prestigious Millennium technology prize

April 13, 2014

Screenshot_4 UK-born physicist Stuart Parkin won the Millennium technology prize 2014. Parkin won this prize for his breakthrough in magnetic disk drive storage capacity.
Parkin’s ground-breaking contribution to the science and application of spintronic materials has led to an abnormal expansion in the capacity to store digital information. Parkin employed the process of Giant Magneto-Resistance (GMR) to produce enormously sensitive devices that can detect tiny magnetic fields, harbingering the epoch of cloud computing. In magnetic disk drives information is stored as “bits” (0s and 1s) mapped by regions of the disk magnetized differently. Thus, if the detector is more sensitive, then the magnetic regions and fields need to be more smaller to store the information, which implies more data can be put on to a hard disk drive – all in digital form. This discovery led to 1,000-fold betterment in the storage capacity of magnetic disk drives with cost remaining almost same.
The foundation behind this award has made services like Facebook, Google, Amazon, etc. possible.
Giant Magneto-Resistance (GMR) and Parkin’s accomplishment:
Giant Magneto-Resistance (GMR) was separately discovered by physicists Albert Fert and Peter Grünberg in the late 1980s and in 2007 they shared the Nobel Prize for physics for their work on GMR. The phenomenon develops when atomically thin layers of magnetic and non-magnetic materials are piled on top of each other. In a plain organization, a non-magnetic layer (typically copper) is sandwiched amid two magnetic layers which act like bar magnets pointing either north or south. On inducing a current in this sandwich, electrons pass through the layers. The degree of interference they go through is dissimilar and depends upon an intrinsic quantum mechanical property of them called “Spin“, which can be adjusted to the direction of the bar magnet or against it. Electrons which have a spin in one direction will travel in a freer manner. Thus, the flow of the current can be checked by the proportional placement of the bar magnets of the top and bottom layers. This phenomenon is called Giant Magneto-Resistance (GMR), as its value is much larger than the MR value received from anisotropic MR that come out from normal ferromagnetic materials.
Parkin’s accomplishment was to prepare a device based on such “Spintronic” effects in which tiny magnetic fields from magnetized regions (that store data within the disk drive) can rotate the direction of magnetization in one of the layers of the sandwich. This outcome is a sensor that quickly goes through large alterations in resistance as it reads the disk drive.