In 1971 Intel's top-of-the-line microprocessors had 2,300 transistors—just over 2,000 on/off switches that carried a computer's binary signal and made all of its computation possible. The microprocessors in today's desktop computers, while still not much bigger than a postage stamp, have more than seven million transistors. The early microprocessor performed about 60,000 calculations per second while today's performs hundreds of millions.

But the trend of the incredible shrinking transistor—and the ever more powerful computer that goes with it—can't continue forever. Many researchers are not confident that transistors can shrink much further at all, much less keep pace with the staggering historical pattern.

"The transistor and silicon roadmap does have an end," says Gerald Iafrate, director of the Center for Nano Science and Technology at the University of Notre Dame. "We're looking at devices that reach beyond the end of that growth."

Quantum-dot Cellular Automata, or QCA, is extending that reach.

QCA is a tiny technology, but its implications are huge. Microprocessors the size of a grain of sand with the power of 100 desktop workstations and computer memory that is incredibly cheap but uses next to no power are just a couple of possible breakthroughs that people mention when they discuss the technology.

QCA theory is less than a decade old, and the first computers to use it are likely a couple of decades away. Nonetheless, an interdisciplinary team of Notre Dame scientists using NCSA's SGI Origin2000 supercomputer and funded by the Defense Advanced Research Projects Agency's Moletronics project is already putting results behind the small talk.

Access Online | Posted 2-29-2000