Supersensitive disk drives on tap

Being able to move electrons from one place to another more efficiently translates to more sensitive electronics that can read information packed more closely on disk drives.

Researchers from the State University of New York at Buffalo have made their ballistic magnetoresistance device 33 times more sensitive by shrinking its electrical contact from 40 nanometers to as small as one nanometer. A nanometer is the length of 10 hydrogen atoms. Ballistic refers to electrons shooting straight through nanoscale circuits rather than bouncing through larger wires.

Disk drives use the change in electrical resistance caused by a magnetic field to sense bits on a disk.

The researchers' method is 100 times more sensitive at room temperature than any type of magnetoresistance currently being developed, paving the way for storage devices that hold several thousand gigabits per square inch. Today's disks hold about 50 gigabits per square inch.

The method could also be used to sense chemicals by measuring subtle differences in electrical resistance.

Biochips that use the technology could be practical within three years, and data storage devices in 5 to 8 years, according to the researchers.

The work appeared in the one February 6, 2003 issue of Physical Review B. -TECHNOLOGY RESEARCH NEWS