Faster data storage using laser pulses to change rare earth elements' 4f electrons' magnetic properties

https://phys.org/news/2024-07-magnetic-properties-rare-earth-elements.html

"strongest magnets based on rare earths, specifically, their 4f electrons, maintained even when chemical environment changes... but for the first time it has now been discovered that 4f electrons' spatial arrangement can be briefly switched by laser excitation, also enabling fast/ energy-efficient control of magnetism... rare earth terbium excited with ultrashort laser pulse...  even faster/ more energy efficient than magnetic heating by laser pulse method current HAMR memory uses"