This year鈥檚 Nobel Prize in Physics has been awarded to researchers whose work paved the way for the miniaturisation of computers hard disks and the emergence of 鈥渟pintronics鈥�.
of the University of Paris-Sud in France and of the Julich Research Centre in Germany share the prize for independently discovering giant magnetoresistance (GMR) in 1988.
The discovery of this phenomenon led to the creation of the tiny hard disks found in laptops and music players like the iPod.
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鈥淭his has had a huge impact on our everyday lives,鈥� says , an expert on nanotechnology at York University in the UK. 鈥淚t鈥檚 the reason you don鈥檛 need to worry about how much software you store on your computer; it鈥檚 certainly a well-deserved award.鈥�
Quantum phenomenon
In 1998, Fert and Grunberg discovered that small magnetic changes to a mix of magnetic and non-magnetic materials can produce large changes in electrical resistance.
When a nanometre-sized layer of a non-magnetic material is sandwiched between two magnetic layers, the spin of electrons in the two outer layers will either line up in parallel with each other, or in opposite directions. It is a tiny change, but one that causes large jumps in electrical resistance.
The effect made it possible to use tiny areas of material to record the ones and zeros of digital data. The result was that information could be packed much more tightly onto hard disks and the size of the disks could be radically reduced.
鈥淕MR is one of those wonderful phenomena from the weird world of quantum physics that has been put to use very quickly,鈥� says Jim Al-Khalili of the University of Surrey.
The discovery of GMR is also considered to be the birth of the burgeoning field of 鈥渟pintronics鈥�, in which information is stored using the quantum spin state, as well as the charge, of electrons. 鈥淪pintronics devices could not only improve the performance of computers, but could allow us to combine information storage and processing on the hard disk in a completely new way,鈥� says Xu.
鈥淲e have seen exciting developments from the first-generation of GMR devices,鈥� he adds. 鈥淚 think we will see some more to come from spintronics with the next-generation.鈥�
