Ultrafast writing with light

https://phys.org/news/2022-12-ultrafast.html

"ultrafast light pulses allowed us to shift the north and south poles of the magnetic domains, which made it possible to skip the electronic intermediate step. It's also possible now to know in advance with certainty whether you'll write a '0' or a '1,' and all without having to know the bit's initial state. That makes it even more efficient... extra atomic layer of the ferromagnetic metal terbium works really well"