Electronics

Fastest-ever logic gates could make computers a million times faster

Fastest-ever logic gates could...
Synchronized pairs of laser pulses drive the fastest logic gates ever made, which could eventually give computers a million-fold speed boost
Synchronized pairs of laser pulses drive the fastest logic gates ever made, which could eventually give computers a million-fold speed boost
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Synchronized pairs of laser pulses drive the fastest logic gates ever made, which could eventually give computers a million-fold speed boost
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Synchronized pairs of laser pulses drive the fastest logic gates ever made, which could eventually give computers a million-fold speed boost

Logic gates are the fundamental building blocks of computers, and researchers at the University of Rochester have now developed the fastest ones ever created. By zapping graphene and gold with laser pulses, the new logic gates are a million times faster than those in existing computers, demonstrating the viability of “lightwave electronics.”

Logic gates take two inputs, compare them, and then output a signal based on the result. They can, for example, output a 1 if both incoming signals are a 1 or a 0, or if either or neither of them is a 1, among other “rules.” Billions of individual logic gates are crammed into chips to create processors, memory and other electronic components.

Logic gates don’t work instantaneously though – there’s a delay on the order of nanoseconds as they process the inputs. That’s plenty fast enough for modern computers, but there’s always room for improvement. And now the Rochester team’s new logic gates blow them out of the water, processing information in mere femtoseconds, which are a million times shorter than nanoseconds.

To reach these extreme speeds, the team made junctions consisting of a graphene wire connecting two gold electrodes. When the graphene was zapped with synchronized pairs of laser pulses, electrons in the material were excited, sending them zipping off towards one of the electrodes, generating an electrical current.

By adjusting the phase of the laser pulses, the team was able to generate a burst of one of two types of charge carriers, which would either add up or cancel each other out – the former can be considered a 1 output and the latter a 0. The end result is an ultrafast logic gate, marking the first proof of concept of an as-yet theoretical field known as lightwave electronics.

“It will probably be a very long time before this technique can be used in a computer chip, but at least we now know that lightwave electronics is practically possible,” said Tobias Boolakee, lead researcher on the study.

If these kinds of lightwave electronic devices ever do make it to market, they could be millions of times faster than today’s computers. Currently we measure processing speeds in Gigahertz (GHz), but these new logic gates function on the scale of Petahertz (PHz). Previous studies have set that as the absolute quantum limit of how fast light-based computer systems could possibly get.

The research was published in the journal Nature.

Source: University of Rochester

5 comments
5 comments
guzmanchinky
This is deeply exciting to think about how much processing power will be available to self driving cars and robots, etc. Jumps like this can be truly world changing.
togaclad
There is a sight error in the numbers. We are working at the ns scale timing path between registers. These often have 50 layers or more of logic so the individual gates are in the 10 pico second range. I'm sure there are others that have pushed past that as well. So not a million but more like 10000 times faster. Still an amazing achievement.
Alien
If is its "a very long time" before these new logic gates come inot general use, perhaps quantum computing will come first.
All sounds very wonderful but still something for the distant future.
martinwinlow
I wouldn't bet that either 'lightwave' electronics or quantum electronics will take 'a very long time' to find their way into an off-the-shelf product - for starters, I'd imagine any company involved in AI will already be developing such technology... including Tesla.
Grunchy
“A million times faster!!!”
The very idea. Why, you look merely at the progress from the 1980s era computers to today, I wonder if that equates to a million-fold increase in power.
In fact, I distinctly remember buying a 3-pack of 360kB diskettes from Radio Shack for $20 and thinking, “I hold enough storage media to hold 1 million bytes!”
The other day I bought a Sandisk 128GB USB device approximately the size of my thumbnail, also for $19.99. Have things really changed to be 1 million times more powerful than they used to be?
Or let’s suppose my 300 baud data communication modem was able to muster 30 characters per second, what would a million-fold increase look like: 30 million bytes per second?