Graphene has the power to change computing forever by making the fastest transistors ever. In theory. We just haven’t figured out how yet. Sound familiar? Fortunately, scientists have just taken a big step closer to making graphene transistors work for real.
Graphene transistors aren’t just fast; they’re lightning fast. The speediest one to date clocked in at some 427GHz. That’s orders of magnitude more than what you can tease out of today’s processors. The problem with graphene transistors though is that they aren’t particularly good at turning off. They don’t turn off at all actually, which makes it hard to use them as switches.
Now, Guanxiong Liu and a team of researchers at University of California, Riverside have come up with a practical, highly technical solution. It boils down to “don’t treat graphene like it’s silicon”.
[Liu and the team] rely on a different phenomenon called negative resistance to create transistor-like behaviour.
Negative resistance is the counterintuitive phenomenon in which a current entering a material causes the voltage across it to drop. Various groups, including this one at Riverside, have shown that graphene demonstrates negative resistance in certain circumstances.
Their idea is to take a standard graphene field-effect transistor and find the circumstances in which it demonstrates negative resistance (or negative differential resistance, as they call it). They then use the dip in voltage, like a kind of switch, to perform logic.
This strategy allows for functional graphene circuits that kick silicon’s arse. The only catch is that you have to design them very differently.
Real applications of this tech, as always, are a still way off in the future, and there’s a lot of testing to be done between now and then. But, hey, we’re making progress. One day, we’re going to see this graphene magic actually take off. Let’s just hope it’s at least kind of soon-ish [MIT Technology Review]