SIN Racetrack Memory: May 2009, Orion K.

A new type of solid-state memory, called racetrack memory (RM), may become the high-speed, high data density, nonvolatile, reliable, and reasonably priced option for data storage. It operates by reading and writing the electrical charge in sections of nanowire imbedded in silicone, and may achieve high data density by using three-dimensional arrays. This was reported by Stuart S. P. Parkin on page 76 of the June 2009 issue of Scientific American; his article was entitled Data in the Fast Lanes of Racetrack Memory (see for a version of the article).

RM tries to combine the benefits of the high write speeds of solid-state memory with the nonvolatile (meaning the data remains when the computer powers down) benefits of magnetic hard disk drives. Miniscule polarized electron spin sections in the RM permalloy wire (a highly magnetic nickel-iron alloy) stores data bits. This is done by assigning each section a 0 or 1 value based on the negative or positive polarized spin. Each section is separated by a “domain wall” where the spin switches from negative to positive or contrariwise. However, to read and write data, these states must pass a read/write head.

In a traditional disk drive, the read/write head moves on an arm, and the disk spins to access the data. However, RM does not need to move anything to access the data. A slight, polarized, electrical pulse could move the domain wall at 150 nanometers per nanosecond, whilst maintaining their spacing. The walls could be moved past heads that can read and write information to and from the wire.

This could reduce computers’ energy consumption and increase their lifespan by reducing moving parts and therefore reducing cooling needs.