Basic science [Technology 1998 analysis and forecast]

The smaller they make their devices, the closer electronics engineers come to entering the world of quantum mechanics, that wonderland where the rules of physics differ drastically from those of the macroscopic world people experience with their senses. In one example, physicists and engineers are creating so-called quantum dots and are investigating how to use them in new forms of electronics. They aspire to transmit data not by tiny currents, but by single electrons that hop from one quantum dot to the next. Probably the one thing generally known about quantum mechanics is that matter-despite its particulate nature-may behave like a wave. This idea was emphasized once again last year when a team at the Massachusetts Institute of Technology (MIT), in Cambridge, produced coherent beams of matter in what the group refers to as an atom laser. (The same group just two years ago produced an entirely new state of matter known as Bose-Einstein condensates.) Elsewhere, scientists in France have succeeded in detecting decoherence, the transition from the quantum world into the macroscopic world, by contriving systems that can be in two quantum states at the same time, albeit briefly. Also in France, physicists have shown how to exploit chaos to encrypt optically transmitted data. This finding might eventually be useful in ultrafast applications, such as the scrambling and unscrambling of television signals transmitted over optical fibers