no On 6/28/09, Sanjay <ilovec...@gmail.com> wrote: > An exotic processor that handles information in the form of waves > rather than current could lead to ultra-low-power processors > > by Jessica Griggs > > MICROCHIPS that process information without moving electrons could > lead to a new generation of ultra-low-power computers. That is the > promise behind a processor that uses waves rather than current to > crunch digital data. > > In conventional computer chips, information is processed in the form > of electric charges and transmitted by physically moving electrons > from one place to another. This approach has been hugely successful, > with engineers packing ever-increasing numbers of transistors onto a > single chip. > > But Moore's law, as this trend is called, is set to come up against a > barrier. As transistors become smaller, tiny variations in the > structure of the materials they are made from can influence the > electron flow. This makes it hard to guarantee that neighbouring > transistors are identical. > > Physicists have been studying another way to process data that may > overcome this problem. In addition to their charge, electrons have a > property called spin, analogous to the spin of a basketball, that can > also carry information. Electron spin can be made to represent a 0 or > a 1 of digital code by aligning it with or against a magnetic field. > > Instead of physically moving the electrons, the information can be > sent in the form of a "spin wave" that travels through the sea of > electrons in a conductor like a ripple moving across a pond. The snag > so far has been to find a suitable way of processing the data carried > by the spin waves. > > Now a team led by Kang Wang at the University of California, Los > Angeles, has built the first logic gate a few micrometres long that > can process the data carried by spin waves. To generate the waves, > electrons are zapped with a magnetic field. The waves then flow along > transmission lines buried in the chip and are processed by making them > interfere, says Wang. > > Wang's logic gates have the potential to work on a much smaller scale > than conventional transistors because they do not rely on a flow of > electrons. Also, as no electrons actually move in this device, less > energy should be lost as heat, says Wang. This could help when it > comes to packing large numbers of these devices onto a microchip, > resulting in ultra-low-power computers. > Spin wave logic gates could work on a smaller scale than today's > transistors > > Wang's group faces numerous challenges in turning the logic gate into > a commercially viable processor. One hurdle is to find a way to split > the signals from one gate so that several gates can be connected > together to form a transistor. > > "The spin wave logic device is very elegant from a physical point of > view, but whether it will really make a device is very difficult to > say," says Del Atkinson from Durham University in the UK. > > > > > To unsubscribe send a message to accessindia-requ...@accessindia.org.in with > the subject unsubscribe. > > To change your subscription to digest mode or make any other changes, please > visit the list home page at > http://accessindia.org.in/mailman/listinfo/accessindia_accessindia.org.in >
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