The Sandia National Laboratories in New Mexico is claiming to have made a breakthrough in transistor design that could lead to devices that can run at a trillion operations per second – ten times the speed of the fastest circuits currently in use. Scientists at the Labs have developed the first reproducable quantum transitor, using electron tunneling, and have already applied for one patent, with others under preparation. But the device, named DELLT, for Double Electron Layer Tunneling Transistor, is unlikely to come to market any time soon, as its use would require wholesale re-design of chips, and perhaps of computer architectures. Sandia says that improvements in transistors of the future may not take the form of a further reduction in size, but instead rely on the radical changes in operation made possible by the new techniques. Using quantum mechanical principles and relying on the dual wave-particle nature of matter, electrons can be made to travel very rapidly over the gallium arsenide transistor circuits, tunneling between barriers that they would not normally have the energy to cross. This can be done at extremely low power rates, and enables the chip to have three positions or states – off-on-off, instead of the two on or off states found in a conventional transistor. The third off state is achieved when the tunneling process occurs. That means that DELLT chips would need significantly less transistors to do the same amount of work as conventional chips. Tunneling techniques have been the subject of research work before, but the Sandia scientists have found a way of stacking up the separate layers within the DELLT chip vertically, rather than side by side. The chips will currently only operate at temperatures at or below 77 degrees Kelvin, 320 degrees Fahrenheit below zero, although Sandia predicts that they will be running at room temperature within a year. Initital applications are likely to be within specialist embedded applications, such as microscopic sensors, where standards have not yet been established.
