IBM’s Racetrack Storage Under Starter’s Orders

IBM has been working on a new storage technology that could allow a mobile device to store the annual output of the worldwide movie industry with room to spare, running on a single battery for weeks at time. IBM’s Almeda Lab reckons that these devices could appear on the market in two to five years time.

The system is known as Racetrack memory because the data moves along a nanowire like cars parading at high speed along a road. The best way to visualise the process is to imagine a magnetic tape recorder where the tape is motionless and the data moves along it to cross the record/playback head.

Flying By Nanowires

The nanowires are rigid threads about a thousandth of the thickness of a human hair and a few microns in length. Along the length of the nanowires data is stored as magnetic regions, called domains. Each domain is separated from the next by what is known as a domain wall. The submicroscopic dimensions of the domains allow the resulting memory to hold at least 100 times more data than today’s devices, with data moving along the “racetracks” at hundreds of miles per hour.

The control of the speeding data is extremely precise, allowing it to be stopped exactly where it is needed. This increased speed of access means that “massive amounts” of data can be accessed in less than a billionth of a second, IBM claims.

The main problem facing the development team was to understand how the domains would move when acted on by electric current pulses. It was not known at first that the walls have mass which means that, instead of stopping dead when the current is removed, the wall’s minute inertia causes it to continue moving an almost-immeasurable, but significant, distance.

“We discovered that domain walls don’t hit peak acceleration as soon as the current is turned on – and that it takes them exactly the same time and distance to hit peak acceleration as it does to decelerate and eventually come to a stop,” said Stuart Parkin, an IBM Research Fellow at Almaden. “Now we know domain walls can be positioned precisely along the racetracks simply by varying the length of the current pulses even though the walls have mass.”

Now this principle is understood, it brings Racetrack memory much closer to marketplace viability. The final devices will be supplied in chip form containing massive arrays of the tiny filaments.

Full details of the discovery can be read in a scientific paper published in the current edition of Science magazine (subscription required).