Just how much data can we cram onto a hard disk? In a paper appearing online
today in Physical Review Letters, EPFL (Ecole Polytechnique Federale de Lausanne)
Professor Harald Brune and his colleagues report what they believe to be the
ultimate density limit of magnetic recording.
His group created a self-assembled lattice of
non-interacting two-atoms-high islands of cobalt
on a single-crystal gold substrate. The islands'
density -- 26 trillion islands per square inch
-- is the highest yet recorded and 200 times the
bit density of current computer hard disks. The
magnetic properties of the islands are the most
uniform ever recorded, and because the islands
don't interact with each other, they can each hold
one bit of data.
However,
it's not a storage medium "ready to use" because
these records were posted at the uncomfortably
cold temperature of -223 C! Above this temperature,
thermal excitation starts to reverse the magnetization
and the information in the memory gets volatile.
Brune and his colleagues are still trying to solve
this blocking temperature problem using bi-metallic
islands of 500-800 atoms that can maintain the
desired magnetic properties at room temperature.
On the web: http://ipn2.epfl.ch/LNS/index.htm .
Author contact info: harald.brune@epfl.ch ;
41-21-693-5451.
Contact: Mary.parlange@epfl.ch
mary.parlange@epfl.ch
41-21-693-7022
Ecole Polytechnique Fédérale de Lausanne
