Better electronics? Start with the switch

U. PITTSBURGH (US) — A new type of switch that performs logic functions within a single molecule could mean smaller, faster, and more efficient electronics.

Scientists discovered the switch by experimenting with the rotation of a triangular cluster of three metal atoms held together by a nitrogen atom enclosed entirely within a cage made up entirely of carbon atoms.

The metal clusters were found to be encapsulated within a hollow carbon cage that could rotate between several structures under the stimulation of electrons. The rotation changes the molecule’s ability to conduct an electric current, thereby switching among multiple logic states without changing the spherical shape of the carbon cage. The concept also protects the molecule so it can function without influence from outside chemicals.


“This new switch is superior to existing single-molecule concepts,” says Hrvoje Petek, professor of physics and chemistry at the University of Pittsburgh. “We are learning how to reduce electronic circuit elements to single molecules for a new generation of enhanced and more sustainable technologies.”

Because of their constant spherical shape, the prototype molecular switches can be integrated as atom-like building blocks the size of one nanometer (100,000 times smaller than the diameter of a human hair) into massively parallel computing architectures.

The prototype was demonstrated using an Sc3N@C80 molecule sandwiched between two electrodes consisting of an atomically flat copper oxide substrate and an atomically sharp tungsten tip.

By applying a voltage pulse, the equilateral triangle-shaped Sc3N could be rotated predictably among six logic states.

The findings, supported by the W.M. Keck Foundation, are published online in the journal Nano Letters. Researchers from the Leibnitz Institute for Solid State Research in Dresden, Germany, and the University of Science and Technology of China contributed.

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