Spintronics based 'Racetrack' Memory from IBM

In two papers published in the April 11 issue of Science, IBM Fellow Stuart Parkin and colleagues at the IBM Almaden Research Center in San Jose describe both the fundamentals of a next-generation nonvolatile memory dubbed "racetrack" as well as a milestone in that technology. "Racetrack" is expected to initially replace flash memory and eventually hard-disk drives.
Using spintronics --the storage of bits generated by the magnetic spin of electrons rather than their charge--a proof-of-concept shift register was demonstrated by this team from IBM. The prototype encodes bits into the magnetic domain walls along the length of a silicon nanowire, or 'Racetrack', so named because the data "races" around the wire "track". IBM uses "massless motion" to move the magnetic domain walls along the nanowire for the storage and retrieval of information.

With these advancements, computer memory that combines the high performance and reliability of flash with the low cost and high capacity of the hard disk drive could be closer than we dreamed of. This milestone could lead to electronic devices capable of storing far more data in the same amount of space than is possible today, with lightning-fast boot times, far lower cost and unprecedented stability and durability.

Currently, there are two main ways to store digital information: solid state random access flash memory, commonly used in devices such as mobile phones, music players and digital cameras, and the magnetic hard disk drive, commonly used in desktop and laptop computers and some handheld devices.

While both classes of storage devices are evolving at a very rapid pace, the cost of storing a single data bit in a hard disk drive remains approximately 100 times cheaper than in flash memory. While the low cost of the hard disk drive is very attractive, these devices are intrinsically slower and, with many moving parts, have mechanical reliability issues not present in flash technologies.
Flash memory, however, has its own drawbacks – while it is fast to read data, it is slow to write data, and it, too, has a finite lifespan. Flash, can be reused only a few thousands of times because it eventually breaks because it is slightly damaged by each use or "rewrite."

Within the next ten years, racetrack memory could lead to solid state electronic devices – with no moving parts, and therefore more durable – capable of holding far more data in the same amount of space than is possible today. For example, this could enable a handheld device such as an mp3 player to store around 500,000 songs or around 3,500 movies – 100 times more than is possible today – with far lower cost and power consumption. The devices would not only store vastly more information in the same space, but also require much less power and generate much less heat, and be practically unbreakable; the result: massive amounts of personal storage that could run on a single battery for weeks at a time and last for decades.



References
[1] "Current-Controlled Magnetic Domain-Wall Nanowire Shift Register"
Masamitsu Hayashi, Luc Thomas, Rai Moriya, Charles Rettner, Stuart S. P. Parkin
Science, Vol. 320. no. 5873, pp. 209 - 211 (11 April, 2008). Abstract Link
[2] "Magnetic Domain-Wall Racetrack Memory"
Stuart S. P. Parkin, Masamitsu Hayashi, Luc Thomas
Science, Vol. 320. no. 5873, pp. 190 - 194 (April 11, 2008). Abstract Link