Single-electron transistors

While the electronics industry wonders what will happen when transistors become so small that quantum effects become important, researchers are building new transistors that actively exploit the quantum properties of electrons. Michel Devoret and Christian Glattli report.

THE INVENTION of the transistor by John Bardeen and William Shockley in 1948 triggered a new era in electronics. Originally designed simply to emulate the vacuum tube, scientists soon found that this solid-state device could offer much more. The great potential of the transistor for speed, miniaturization and reliability has been fully exploited since well controlled materials such as pure single-crystal silicon became available. According to the latest "road-map" for the microelectronics industry, microchips containing one billion transistors and operating with a clock cycle of a billionth of a second will be on the market just a few years into the new millennium...