Carbon Nanotube Functions Like Atom-scale Switch

Their approach is to perform first-principles calculations on positioning a molecule inside a carbon nanotube to affect the electronic current flowing across it.

The result is an electrical gate at the molecular level: In one position, the molecular gate is open, allowing current through; in another position, the gate is closed, blocking the current. In a silicon chip, the gate is a silicon oxide barrier within the structure of the chip. In the ORNL model, the gate is a short molecule --encapsulated inside the carbon nanotube-- that is about one nanometer in size, or three orders of magnitude smaller than a silicon chip.

The paper is slated to appear in the Feb 2 Physical Review Letters.