Japanese scientists have discovered a method of changing magnetic domains – such as those used in RAM and hard-drives – using magnetic fields rather than the current process of electromagnets, in a system that could see storage become faster and more energy efficient. Magnetic domains, tiny regions inside magnetic materials that behave as individual magnets and can be flipped from north to south, are currently manipulated by an electromagnet, encoding binary 1 or 0. With the new system that electromagnet is bypassed: applying voltage to a nearby electrode creates an electric field that shifts the domains.
The Tohoku University team took advantage of the fact that, in some materials, orientation of magnetic domains is related to the density of charge carriers (e.g. electrons) inside them. They used an iron-based semiconductor and were able to rotate domains by 10-degrees.
This is obviously short of the 180-degrees necessary to encode binary, but the researchers are working on tweaking the chemistry of the material to make that rotation possible. Eventually the system could be used to make MRAM, which could be more power efficient and faster than STT-RAM.