Magnetizing the Third Dimension

Hard disk drives store data in magnetic materials where each bit of information is encoded in a 2D pattern of the material’s magnetization direction. The size of bits has rapidly decreased since the first hard disk drive was made in 1956, leading to a significant increase in the recording capacity. But miniaturization can’t go on forever. To meet ever-increasing data storage needs, future devices will need to move into the third dimension. Hirofumi Suto and colleagues at Toshiba Corporation in Japan have demonstrated a new 3D magnetic structure where the magnetization of each layer can be independently switched from one state to another in a single step.