Single molecule transistor

Principal investigator Dr. Robert Wolkow, postdoctoral fellow Dr. Paul Piva and a team of researchers from the

and the

of the Canadian

have designed and tested a new concept for a single molecule transistor.

They have shown, for the first time, that a single charged atom on a silicon surface can regulate the conductivity of a nearby molecule. Their research is published in the June 2, 2005 edition of the scientific journal Nature.

Miniaturisation of microelectronics has a finite end based on today’s technology. A new concept to circumvent the limits of conventional transistor technology was needed. The authors conducted an experiment to examine the potential for electrical transistors on a molecular scale. Their approach has solved what has been an insurmountable hurdle to making a molecular device: getting connections onto a single molecule.

They demonstrated that a single atom on a silicon surface can be controllably charged, while all surrounding atoms remain neutral. A molecule placed adjacent to that charged site is 'tuned', which allows electrical current to flow through the molecule from one electrode to another. The current flowing through the molecule can be switched on and off by changing the charge state of the adjacent atom.