3,5" and 2,5" hard disk drives opened on a blue background
March 9, 2017

IBM figured out how to turn a single atom into a hard drive

As part of the never-ending quest to store more and more data in increasingly smaller spaces, a team from IBM Research has announced that it has managed to discover a way to read and write data to and from a single atom – a breakthrough detailed this week in the journal Nature.

While as TechCrunch pointed out, the work is “more symbolic than practical right now,” it is a big advance over current systems that require thousands of atoms to store information and could lead to a future device capable of storing tens of millions of songs to any given mobile device.

As the researchers wrote in their study, “The single-atom bit represents the ultimate limit of the classical approach to high-density magnetic storage media.” Most current hard drives require up to 100,000 atoms to store a single bit of data, CNET said, while the smallest stable, individually addressable magnetic bits has consisted of between three and 12 atoms, the authors noted.

While, as PC World reported, some other tech gurus have developed single-atom storage systems previously, those were not magnetic in nature. Magnetic storage, the researchers explained, is the technique currently used by hard disks and flash drives and is solid state, meaning that it does not require atoms to be moved around to work.

view of atom used in IBM hard drive

The holmium atom used IBM to store a 1 or 0.
(Credit: IBM research)

Don’t expect to see this in commercial devices anytime soon

Christopher Lutz, the nanosciences expert who led the IBM Research project, told PC World that after his team successfully made one atom store a bit, they put two atoms near each other to learn how close they could be while still maintaining the ability to be read independently.

They found that the atoms still functioned while less than one nanometer apart, meaning that it is theoretically possible to store up to 600 terabits per square inch using this technique. This would greatly help data-hungry artificial intelligence and machine-learning systems, while also making it possible for a business to store all of their data on a smartwatch, according to CNET.

Chris lutz standing by an atomic microscope

IBM researcher Chris Lutz by a microscope used to store a bit of data on a single atom. Credit:
IBM and Stan Olszewski/SOSKIphoto

So exactly how did IBM pull this off? According to TechCrunch, they took a single Holmium atom (a large atom that contains several unpaired electrons) and placed it on a magnesium oxide bed, giving it magnetic bistability, meaning it has two stable magnetic states with different spins.

Next, they used a scanning tunneling microscope (STM) to apply roughly a 150 millivolt shock at 10 microamps to the atom, which caused the Holmium atom’s magnetic spin state to be altered. Once they confirmed that the atom was indeed changing its magnetic state, they set an iron atom down nearby, and based on the reaction of the atom, they could tell which magnetic state it was in at the time – essentially the equivalent as storing a 0 or a 1 in terms of data.

While this is an exciting development, consumers shouldn’t expect to see devices that take advantage of this technology anytime soon, Lutz warned. As he told PC World, the experiment was purely conceptual and designed to achieve the maximum possible storage density, with an eye towards future breakthroughs in the field. The single-atom technique required conditions impossible to replicate in commercial devices, he noted.

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