The world's smallest magnetic data storage unit

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Twelve iron atoms make up the world's smallest magnetic data storage unit to date. The antiferromagnetic order in the iron atom array is revealed by spin-polarized imaging with a scanning tunneling microscope

Don't hold your breath but it's still exciting

Scientists from IBM and the German Center for Free-Electron Laser Science (CFEL) have built the world's smallest magnetic data storage unit. It uses just twelve atoms per bit, and squeezes a whole byte into as few as 96 atoms. A modern hard drive, for comparison, still needs more than half a billion atoms per byte.

Just imagine HDDs based on this technology, that'd be really cool

The nanometre data storage unit was built atom by atom with the help of a scanning tunneling microscope (STM) at IBM's Almaden Research Center in San Jose, California. The researchers constructed regular patterns of iron atoms, aligning them in rows of six atoms each. Two rows are sufficient to store one bit. A byte correspondingly consists of eight pairs of atom rows. It uses only an area of 4 x 16 nm. "This corresponds to a storage density that is a hundred times higher compared to a modern hard drive," explains Sebastian Loth of CFEL, lead author of the Science paper.

Data are written into and read out from the nano storage unit with the help of an STM. The pairs of atom rows have two possible magnetic states, representing the two values '0' and '1' of a classical bit. An electric pulse from the STM tip flips the magnetic configuration from one to the other. A weaker pulse allows to read out the configuration, although the nano magnets are currently only stable at a frosty temperature of minus 268 degrees Centigrade (5 Kelvin). "Our work goes far beyond current data storage technology," says Loth. The researchers expect arrays of some 200 atoms to be stable at room temperature. Still it will take some time before atomic magnets can be used in data storage.

That's how it looks like



Iron atoms are placed onto a copper nitride surface and bound by two nitrogen atoms (blue rods) into a regular array separated by one copper atom (yellow).

I like their approach:

For the first time, the researchers have managed to employ a special form of magnetism for data storage purposes, called antiferromagnetism. Different from ferromagnetism, which is used in conventional hard drives, the spins of neighbouring atoms within antiferromagnetic material are oppositely aligned, rendering the material magnetically neutral on a bulk level. This means that antiferromagnetic atom rows can be spaced much more closely without magnetically interfering with each other. Thus, the scientist managed to pack bits only one nm apart.

http://www.physorg.com/news/2012-01-...c-storage.html

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Storing data in individual molecules

An experimental technology called molecular memory, which would store data in individual molecules, promises another 1000-fold increase in storage density. In the Jan. 23 online edition of Nature, an international team of researchers led by Jagadeesh Moodera, a senior research scientist in the MIT Department of Physics and at MIT's Francis Bitter Magnet Laboratory, describes a new molecular-memory scheme that works at around the freezing point of water - which in physics parlance counts as "room temperature." Moreover, where previous schemes required sandwiching the storage molecules between two ferromagnetic electrodes, the new scheme would require only one ferromagnetic electrode. That could greatly simplify manufacture, as could the shape of the storage molecules themselves: because they consist of flat sheets of carbon atoms attached to zinc atoms, they can be deposited in very thin layers with very precise arrangements.