author : Brewster, Signe
source : GigaOm
In pursuit of graphene-based electronics, researchers rethink their logic
Graphene, a one-atom-thick sheet of carbon atoms with amazing physical properties, has been touted as the next silicon. Electrons move through it with ease, making it an ideal pick as a semiconductor in electronics like phones and computers.
But graphene has a big problem: It can’t be turned “off” like silicon. The electrons flow continuously, which is a huge obstacle that must be overcome before graphene has a chance of challenging silicon as a material that can generate the 0s (“off”) and 1s (“on”) that are the basis of computing.
University of California-Riverside researchers just announced they have come up with a possible solution. Most research has focused on modifying the graphene itself, whether by stacking it with other materials or introducing impurities, without much luck.
“We decided to take an alternative approach,” electrical engineering professor Alexander Balandin said in a release. “Instead of trying to change graphene, we changed the way the information is processed in the circuits.”
Silicon’s ability to start and stop the flow of electrons works well with Boolean logic, a means of processing information. Information is encoded and processed as a series of 0s and 1s; when electrons are flowing, a computer records a 1, and when they’re not flowing, it records a 0.
Because graphene can’t turn off the flow, Boolean logic doesn’t work. So the UC-Riverside researchers invented a different kind of logic that takes advantage of graphene’s unique properties. Instead of turning the flow of electrons on or off, they instead manipulated the voltage and current to represent different values. As a result, it doesn’t matter if the electrons are flowing constantly.
The researchers were able to show that the system worked at a microscopic scale, but also at the nanometer scale that computing is moving toward. Increases in computing power rely in part on ever-smaller transistors, which carry electronic signals to serve a few different purposes. Building them out of graphene could lead to transistors that are just an atom wide, allowing manufacturers to pack in more for more powerful computers.
Boolean logic is integral to the mobile and desktop computers we use every day. That’s been the case for decades now, so throwing it out altogether is a radical idea. It could also require manufacturers to build chips in very different ways from current silicon-based chips. This could complicate a shift to graphene, and it might require software programmers to think very differently. At the very least, the research shows there may be more options looming for working with graphene, despite how it handles electrons.
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