Transistors are the basic elements of integrated circuits: they control the flow of current between two electrodes (called "source" and "well" or "discharge") by changing the voltage applied to third electrode ( "gate" or "gate") . The aim of nanotechnology has long been the construction of a transistor in which the electrodes are separated by a single molecule in which the electrons to flow.
This is not the only way to explore the possibility of linking to a molecule, but only the first - in which the current was successfully controlled by varying the energy of molecular orbitals, ie the "cross" on which run its electrons. Organic molecules seem the ideal candidate, but so far nobody has been able to work circuits so small.
To build their transistor, the researchers placed on a layer of aluminum oxide coated with gold threads of benzene, an organic molecule, and later broke the golden threads by creating micro-fractures. In the most fortunate cases, in a micro-fracture can remain trapped one molecule of benzene. In this way, the researchers recreated a micro-transistor, where the ends of the wires were broken once in the spring, the other shaft, aluminum oxide made by hand at the base gate. In this way, the molecule of benzene has become the electrical junction between the electrodes of the micro-transistors.
By applying different voltages to the door, the researchers manipulated the energy of the molecular orbitals of benzene, by controlling the intensity of current that flows between sources and sinks through the molecule. "It 'like a ball rolling up and down a mountain," says Reed, one of the authors of the study appearing in Nature. "The ball is the current and the height of the mountain is the different energy states of the molecule. We can adjust the height of the mountain. " The researchers state that their results are a purely scientific victory, and it will take many years before we could use the molecular transistors in the circuits of computers.