Researchers close in on atomic storage target

Computerworld - A group of physics researchers have created a device that's able to store one bit of data in one atom, according to published data from a member of the research team.
Franz Himpsel and a team from the University of Wisconsin-Madison have used a scanning tunneling microscope traveling over a silicon surface, the tip of which can detect the presence of a single silicon atom that can be used to represent binary zero or binary one.
At this stage, the data silicon atom must be separated from its neighbors by placing it in a five-by-four cell of atoms, and therefore requires 20 atoms in all to securely store one bit, according to data published on the university's Web site.
This translates into a storage density of 250T bits per square inch, which is 2,500 times denser than the 100G bits per square inch that can be stored on the most advanced conventional hard disk drives, Himpsel said.
The atomic memory on silicon device has been tested for reliability and speed. Reading data can be achieved at a reasonable rate, although slower than in hard disk drives, but writing data at the maximum data density is currently too slow to be practical, according to Himpsel.
One potential way to speed up data reads and writes would be to use a large number of scanning tunneling microscopes in parallel, with up to 1,000 scanning tunneling microscope tips in an array, Himpsel said.
IBM is also conducting research into data storage using a variation on the scanning tunneling microscope. The company says its Millipede technology, capable of storing 1T bit per square inch, could start appearing in products as early as 2005 (see story).
The idea for an atomic memory storage device was conceived as early as 1959 by U.S. physicist Richard Feynman, who described in a talk a memory cube containing 125 atoms being able to store one bit.