Era of the quantum computer beckons

Scientists at Cambridge University have found a way to mass-produce miniature circuits that could herald a new era in electronics.

The development will mean circuits can be packed into ever smaller volumes, holding out the promise of computers hundreds of times faster than today's, with memories a thousand times larger.

Michael Pepper, who heads the research team, said this new technology would mean a 'radical transformation' of electronics.

He said it was as big a step forward as the jump from single transistors to integrated circuits in the late 1950s which marked the start of the microprocessor era and spawned today's computing and telecommunications revolution.

Millions of transistors are now crammed on to single semiconductor chips.

But this technology is reaching its limit, set by the wavelength of light.

The next step, vital if computers are to continue getting smaller and more powerful, involves the use of so- called 'quantum devices'.

Such devices have dimensions about 100 times smaller than the wavelength of visible light, operating at the scale of a few individual electrons. They will be crucial to the consumer electronics of the 21st century, when personal computers, mobile telephones and faxes are expected to be combined in single, portable units.

Until now, most quantum devices have been exotic laboratory creations. The new development allows the researchers to build tiny quantum dots and wires from a few electrons to form circuits, switches and interconnecting links.

Most importantly, the approach will enable researchers to grow lots of these tiny devices on a wafer of semiconductor material, making mass production a possibility.

Professor Pepper's devices still operate only at extremely low, cryogenic temperatures that rule out practical application. His work, funded by Toshiba, will probably not yield commercial products until the turn of the century.