Japanese scientists have reportedly created 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.