Leading Edge R&D:

NANOMAGNETS: HUGE POTENTIAL FOR COMPACT INFORMATION STORAGE

Chemists are developing tiny magnets based on single molecules that could potentially increase digital-information storage densities 10,000 times -- to 30 terabits per square centimeter. Single-molecule magnets containing manganese show particular promise.

In research supported by NSF, George Christou of the University of Florida and his collaborators developed a technique for controlling the quantum properties that previously presented an obstacle to using these nanoscale magnets.

In a typical digital magnetic recording device, the direction of alignment of the magnetic field represents one bit of information (for a computer, 0 or 1). When the recording domain is shrunk to the nanoscale, magnets display a quantum property in which their magnetization "tunnels" through an alignment barrier, causing a change in alignment and loss of the stored information.

Christou's group has found a way to pair two of the single-molecule magnets in a fashion that suppresses this quantum property. The quantum tunneling can be switched back on by applying a magnetic field of an appropriate strength. Their technique offers a way to fine-tune the properties of these nanoscale magnets and removes a major hurdle to their use in high tech devices.