January 13, 2012, 6:01 PM — I can't say I've ever really needed to know this, but, according to IBM researchers, storing a single bit of data on a disk drive requires one million atoms of magnetized storage medium.
The only reason it's important to know that now is that IBM's Almaden Research Center is touting a new approach to magnetic storage that requires as few as 12 atoms worth of medium to store a single bit of data.
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Existing magnetic storage media – hard drives, just to stick to one form factor – are designed with all the magnetic poles of all the atoms aligned in the same direction.
When they're exposed to a magnetic field, ferromagnetic materials like iron, nickel and other metals used in storage media line up and coordinate not only their magnetic poles, but the orbits of unpaired electrons as well.
The opposite condition – antiferromagnetism – in materials such as manganese oxide causes atoms to align head-to-foot so that the North magnetic pole of each atom seeks the South magnetic pole of another.
That focuses more of the magnetic field within the material itself. Because all the atoms expose the same magnetic pole in the same direction, the magnetic field in ferromagnetic materials reaches farther, and is easier to read than antiferromagnetism.
Similar magnetic poles push each other apart powerfully enough to levitate mag-lev bullet trains, or create more distance between atoms in a magnetic storage medium than would be the case if all those aligned magnetic poles weren't so repelled by one another.
The IBM Almaden center used the attraction of anti-ferromagnetic atoms to create a swathe of material with a much denser magnetic palette than typical ferromagnetic surfaces.
The atoms attract one another so closely and create a storage surface so dense that they can store more than 100 times as much data on the same number of atoms as more traditional media, according to Andreas Heinrich, the IBM Almaden researcher who led the research to develop the denser medium.
The paper describing their work was published in the current issue of Science.
The big problem with the new medium is the amount of work it takes to create it and temperature required to make it work.
IBM Almaden Research Center