Japanese scientists have created
the first controllable silicon transistors that are turned on and off
by the motion of individual electrons.

Researchers said the experimental
devices — designed and fabricated at the NTT Corp. of Japan — were
tested at the National Institute of Standards and Technology in
Boulder, Colo., and may have applications in low-power nanoelectronics,
particularly as next-generation integrated circuits for logic
operations.

The transistors
are based on the principle that, as device sizes shrink to the
nanometer range, the amount of energy required to move a single
electron increases significantly. That, scientists said, makes it
possible to control individual electron motion and current flow by
manipulating the voltage applied to barriers, or gates, in the
electrical circuit.

At
negative voltage, the transistor is off; at higher voltage, the
transistor is turned on and individual electrons file through the
circuit, as opposed to thousands at a time in a conventional device.

The development is described in the Jan. 30 issue of Applied Physics Letters.