Scientists at Sandia National Laboratories in Albuquerque, N.M., have developed a quantum mechanical transistor that may increase the accuracy of optical detectors and energy spectrometers. The transistor takes advantage of a phenomenon described in quantum physics as electrons tunneling from path to path through a normally impenetrable barrier. The atomic-scale effect may take place as fast as a trillion operations a second -- about 10 times the speed of the fastest transistor circuits currently in use. According to its leader, Jerry Simmons, the team has demonstrated working circuits that are easy to fabricate. Because of the device's tunability, it could act like an energy spectrometer on a chip. Other suggested uses include an optical detector in the far infrared. In that capacity, incoming photons would be used to add energy needed for a transition between electron states.