A group of physics researchers have created a device which is able to store one bit of data in one atom, according to published data from one of the research team.
Franz Himpsel and a team from the University of Wisconsin have used a scanning tunneling microscope (STM) travelling over a silicon surface, the tip of which can detect the presence or absence of a single silicon atom, which 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, the scheme therefore requiring 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 HDDs, 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 STMs in parallel, with up to 1,000 STM tips in an array, Himpsel said.
IBM Corp. is also conducting research into data storage using a variation on the STM, and believes its Millipede technology, capable of storing 1T bits per square inch, could start appearing in products as early as 2005.
The idea for an atomic memory storage device was conceived as far back as 1959 by the U.S. physicist Richard Feynman who described in a talk a memory cube containing 125 atoms being able to store one bit.
Further information on the atomic memory on silicon research can be found at http://uw.physics.wisc.edu/~himpsel/memory.html