AsianScientist (Jan. 21, 2015) – Humanity has entered a new age of information access. We are now able to store ever-increasing amounts of data in ever-shrinking devices. In a single decade, we have moved from a world of analog, where data is stored in physical forms such as books, to a digital one.
Speaking at the Global Young Scientists Summit (GYSS@one-north) 2015, which is taking place from 18-23 January 2015 at Singapore’s Nanyang Technological University, Professor Stuart Parkin, recipient of the 2014 Millennium Technology Prize, marveled that the disk drive revolution of the last half-century has been nothing short of remarkable.
“A disk drive from 1962 would have been 24 inches in diameter, requiring 50 such disks just to store 28 megabytes of data. More than 50 years later, I myself now own a 2.5-inch personal disk drives that carries 1,000 GB (1 TB) over just a single disk,” he quipped. “Now, every piece of information known to mankind can be stored digitally—and can be used in forms that were not possible just a few years ago.”
The digital storage revolution has in turn driven the creation of companies that store large amounts of data in the cloud, such as Facebook, Apple’s iTunes and iCloud, Amazon Cloud Services, Netflix, Google, Twitter, Dropbox, Instragram and many more. Incidentally, these companies happen to be the some of the most profitable and ubiquitous.
And they all have Parkin—who is presently an IBM Fellow and Director at the Max Planck Institute for Microstructure Physics in Halle, Germany—to thank for their success. The technology behind this cloud computing age is called spintronics, which was developed by Parkin’s team and which allows for a thousand-fold increase in storage capacity.
Spintronics uses the magnetic spin of electrons (as opposed to the flow of electrons) to store ‘bits’ of information very efficiently. Incredibly large chunks of information can be stored in the ‘cloud’—centralized data storage servers that may be located thousands of miles away from the user—and accessed within seconds by a push of a button.
Sputtering and spin valves
Magnetism is an early protagonist of the information technology revolution, explained Parkin, who has been a distinguished visiting professor at the National University of Singapore since 2007.
“The very first form of digitally storing data was through magnetic core memory. This technology used tiny rings of made from solid magnetic material, and was the predominant form of random-access computer memory (RAM) during the 1950s to 1970s.”
There’s a reason the technology didn’t survive into the ’80s—it proved too difficult to scale down to smaller dimensions. Magnetic core memory had a storage capacity of 3,000 bits, which would not even have been enough for a small picture file.
How, then, to improve the storage capacity of electronic devices? Parkin started exploring the then newly-discovered phenomenon called giant magnetoresistance (GMR). He used a mass-manufacturing process called sputtering to increase the density of magnetic disk drives—an undertaking that would involve the testing of over 10,000 different materials.
Sputtering can be thought of as a way of coating a material that is similar to throwing apples into a tub of water and letting the splashes paint the carpet beneath it, using high energy atoms instead of apples.
Aside from sputtering, another major achievement of Profesor Parkin was in developing a tiny device that would change the face of digital storage technology forever: the spin valve.
“The development of spin vales, which are incredibly sensitive detectors of tiny magnetic fields, enabled increases in the speed and capacity of the disk drives by more than 1,000-fold within five years,” he shared.
Indeed, it was only a few years ago that all the disk drives manufactured in one year, 2002, could store all information that was known to mankind at that time. Exactly a dozen years later, Parkin’s ground-breaking work would net him the prestigious 2014 Millennium Technology Prize—and the street cred of kickstarting the modern digital economy.
Stepping into the third dimension
But is it all downhill from here? As Parkin explained, magnetic disk drives are a two-dimensional technology, involving only a single magnetic layer in which we store magnetic bits.
“For last 50 years progress has been made by continual shrinking the size of these magnetic regions,” he noted. “But we have reached the end of the road map for this technology. The storage capacities of magnetic disk drives are now seeing only a ten percent increase per year.”
Referencing one of the tallest buildings in Singapore, the Swissotel Stamford, Parkin suggested following Singapore’s example of building upwards by moving into the third dimension.
“Today’s two-dimensional technologies will need to evolve into innately three-dimensional technologies both in terms of memory and storage,” he emphasized.
Three-dimensional technologies could be possible by applying a new concept in spintronics that he proposed back in 2002, called racetrack memory. Magnetic disk drives would store information in the third dimension, using tiny nanoscopic wires to connect the layers, he explained.
“With racetrack memory, we could have a product that has the same storage capacity as a magnetic disk drive, but a million times faster. It would never wear out, it would use less energy, and it would also be much smaller,” said Parkin, whose team has since built an early prototype with 32 ‘racetracks’.
“The physics is even more interesting and exciting than we had anticipated. From spin-orbit derived phenomena, we are now able to move a series of magnetic domains around this ‘racetrack’ at speeds approaching one kilometer per second.”
If racetrack memory is someday made commercially available, it could be as disruptive as the spin valve proved to be for data storage, Parkin noted.
“It could displace flash memory—which is one of the two largest solid state memory technologies at present. Eventually it could even replace magnetic disk drives,” he said, tantalizing the audience with visions of the next exciting age of information.
Asian Scientist Magazine is a media partner of the Global Young Scientists Summit (GYSS@one-north 2015), taking place from 18-23 January, 2015 at Nanyang Technological University, Singapore. GYSS@one-north 2015 is organized by the National Research Foundation of Singapore in collaboration with its partners.
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Copyright: Asian Scientist Magazine.
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