from the very-small-but-very-slow dept.
Gina Miller writes "A Sept. 3 press release from the University of Wisconsin at Madison Scientists develop atomic-scale memory reports that scientists have been able to read and write at room temperature to a memory that uses a single atom to store a bit. Silicon atoms are dispersed on a self-assembled surface of gold atoms so that each silicon atom fits into a pocket formed by 20 surrounding gold atoms. An STM tip is used to remove specific silicon atoms to write to the memory. Although the storage density is very high, writing with an STM tip is very slow." More details (and pictures) are available on the researchers' web site: Nanoscale Memory. The original research was published in Nanotechnology 13 (2002) 499-502: "Atomic scale memory at a silicon surface"
The limits of pushing storage density to the atomic scale are explored with a memory that stores a bit by the presence or absence of one silicon atom. These atoms are positioned at lattice sites along self-assembled tracks with a pitch of five atom rows. The memory can be initialized and reformatted by controlled deposition of silicon. The writing process involves the transfer of Si atoms to the tip of a scanning tunnelling microscope. The constraints on speed and reliability are compared with data storage in magnetic hard disks and DNA.
A brief account of this research was published by BBC News: Atomic memory developed "Imagine a CD with a storage capacity not of 650 MB but 650 million MB. Such a storage capacity is theoretically possible because of experiments using individual atoms to store data. … But while theoretically it is possible to use single atoms as storage bits, in practice it may take decades to make a practical version of atomic memory."