This is some great research, the paper is here: https://www.nature.com/articles/s41467-025-59675-5.pdf and there are two things that stand out in it, the first is that they used a "commercial graphene transistor" and the second is that their apparatus didn't need to be super-cooled or under tens of atmospheres of pressure or in vacuum etc. For me, that means that the risks of bringing this into an actual thing are much less than they have been for other technologies (like Josephson-Junctions).

It's also kind of funny that you could mine the shit out of Bitcoin with something like this, which would either pay for itself or crash Bitcoin, hard to predict.

So rather than electrons flowing through regular transistors you would have photons flowing through phototransistors? Wouldn't one problem be casting light rays that with widths in the nano or picometer range?

This seems very huge, or am I missing something fundamental that's not included in the paper?

Petahertz?

It makes me raise so many questions. 1 PHz corresponds to a wavelength of 300nm, UV light. How does it make sense? It can't be the transistors we are used to, that's all quantum weirdness at this point. How do you even use them? Things like copper wires feel meaningless at these scales.

At that clock rate, propagation delays are going to be a severe issue.

> A study published in Nature Communications highlights how the technique could lead to processing speeds in the petahertz range – over 1,000 times faster than modern computer chips.

A 1 petahertz chip would be 200,000 faster than a 5 gigahertz chip. You've skipped past the terahertz range.

https://www.nature.com/articles/s41467-025-59675-5 is the paper, claiming "~1.6 petahertz speed." That would be 190-nanometer wavelength, which is into the so-called "far ultraviolet" band of germicidal UVC, 6.6eV photon energy, on the edge of vacuum ultraviolet. And they're switching it with light. So, I wonder how long these devices will last if you keep using them?

They say the light pulse is 6.5fs FWHM, so they weren't able to switch it on and off 1.6 quadrillion times per second; it's just that the transition from on (29nA) to off (<1nA) was only 630 attoseconds long, which is what they're describing as "petahertz". But "petahertz" implies a whole cycle time under a femtosecond, a cycle which would involve two transitions, which would presumably be 1.26 femtoseconds at this speed. (If they measured the speed of the off-to-on transition, I missed it skimming the paper.) And the actual light they're making the 6.5fs pulse out of is a "supercontinuum laser beam that spans over 400–1000 nm". That's still blue enough to raise some concerns about device longevity (though maybe graphene will prove tougher than certain other semiconductors which shall not be named here), but not to the same degree as if they were using actual petahertz light.

I think the 2× exaggeration is sort of forgivable, and nothing else seems to be intentionally misleading, but it would still be easy to draw incorrect conclusions from the headline.

Moore's Law ain't over til it's over.

I can't wait to watch cat videos at petahertz speed.