Racetrack memory is an experimental form of memory that looks to combine the best attributes of magnetic hard disk drives (low cost) and solid state memory (speed) to enable devices to store much more information, while using much less energy than current memory technologies. Researchers at IBM have been working on the development of Racetrack memory for six years and have now announced the discovery of a previously unknown aspect of key physics inside the new technology that brings it another step closer to becoming a reality.
Instead of making computers seek out the stored data it needs, as is the case with traditional computing systems, Racetrack memory automatically moves data to where it can be used by sliding magnetic bits back and forth along nanowire “racetracks.” The researchers say that, because the data is stored as magnetic patterns – also known as domains – in racetracks just a few tens of nanometers wide, the technology would allow for portable devices to be created that could store all the movies produced within a given year with room to spare.
IBM has already proven that domains can act as nano-sized data keepers that can store at least 100 times more information than today’s techniques and can also be accessed at much greater speeds. The domain walls are moved at speeds of hundreds of miles per hour and stopped precisely at the position needed by controlling electrical impulses in the device, thereby allowing massive amounts of stored information to be accessed in less than a billionth of a second.
Now, for the first time, the researchers have been able to measure the time and distance of domain wall acceleration and deceleration in response to electric current pulses, which allows the precise control of the placement of the domains.
“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 Dr. Stuart Parkin, an IBM Fellow at IBM Research – Almaden.
“This was previously undiscovered in part because it was not clear whether the domain walls actually had mass, and how the effects of acceleration and deceleration could exactly compensate one another. 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,” Parkin added.
This surprised the scientists because previous experiments had shown no evidence for acceleration and deceleration for domain walls driven along smooth racetracks with current.
The scientists say that, aside from giving them an unprecedented understanding and control over the magnetic movements inside these devices, the discovery also brings Racetrack memory closer to marketplace viability. It is also likely to be of interest to other researchers working on the technology.
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