SPIN CITY

Nanotechnology pioneers win 2007 physics Nobel 

France's Albert Fert and Germany's Peter Gruenberg have won the 2007 Nobel Prize for Physics, recognised the pair's discovery of giant magnetoresistance, which has helped revolutionise computer data storage and retrieval.

Harnessing these tiny magnetic changes - dubbed spintronics - made it possible to pack much more data onto hard disks and the development of handheld devices such as mobile phones or music players.

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The giant magnetoresistive effect (GMR) is a quantum mechanical effect observed in thin film structures composed of alternating ferromagnetic and nonmagnetic metal layers. The 2007 Nobel Prize in physics was awarded to Albert Fert and Peter Grünberg for the discovery of GMR.

The effect manifests itself as a significant decrease in resistance from the zero-field state, when the magnetization of adjacent ferromagnetic layers are antiparallel due to a weak anti-ferromagnetic coupling between layers, to a lower level of resistance when the magnetization of the adjacent layers align due to an applied external field. The spin of the electrons of the nonmagnetic metal align parallel or antiparallel with an applied magnetic field in equal numbers, and therefore suffer less magnetic scattering when the magnetizations of the ferromagnetic layers are parallel.