IBM's Faster, Denser Memory

Researchers led by Stuart Parkin are developing a new type of memory chip that combines the benefits of magnetic hard drives and flash.

Big Leap: Stuart Parkin of IBM, pictured here, is well known for his advances in the magnetic read head technology that are used in hard disk drives. Now he’s developing a new type of magnetic memory, called racetrack memory, that could be faster, more compact, and more rugged than hard disks.

Racetrack memory consists of an array of billions of nanowires on silicon; each nanowire is able to hold hundreds of bits of data. Because the nanowires are so small, racetrack memory has the potential to be many times more dense than Flash. Unlike Flash memory, in which bits are stored as electrical charges in a transistor, racetrack memory stores data as a series of distinct magnetic fields along the wire. Flash memory degrades over time as charges leak and memory cells wear out, but racetrack memory, which uses magnetic fields, doesn't have this problem. And compared to the hard disks used in laptops and PCs, which store data on a bulky, spinning platter, racetrack memory has no moving parts and can be built in silicon, making it more robust.
Data is encoded onto racetrack memory by changing the magnetic properties along the wire, creating a series of magnetic barriers--called domain walls--and gaps between. Just as electrical charge represents a bit in a Flash memory cell, the gaps between two domain walls represent bits in racetrack memory. To read and write data from the nanowire, the domain walls move along the tracks, single file, past where stationary read and write heads are positioned.

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