Your phone, your laptop, the cloud where your photos live: they all store data as tiny magnetic bits. Flip one way, it's a 1. Flip the other, it's a 0. Today we flip them with magnetic fields. It works, but it's slow.
The idea
Engineers at the University of California San Diego flipped the bits with light instead. They shaped a very short laser pulse into a tiny beam and pointed it at a sandwich of nine alternating layers of platinum and cobalt.
That's the big step. Earlier experiments only worked with up to three layers. More layers means more data in the same spot.
How fast?
Switching with light could be more than 1,000 times faster than the magnetic way. And the beam didn't need any special type of light to work.
"The smaller the size of the beam, the smaller and more dense the optical memory," says Abdoulaye Ndao, the senior author. The team wants to shrink the beam to a few hundred nanometres, about a thousand times thinner than a hair.
The catch
The laser used is not easy to put inside a computer chip yet. So this is a lab result, not a product you can buy at Christmas.
But if it works out, files could save in a blink, and data centres could do more with less power. For now, your phone will still take its time loading that one app you need right now.