Atomic laser points the way to future

It could become the most precise manufacturing tool that humans ever build. Physicists in the United States have demonstrated the world's first "atomic laser", in which atoms take the place of light, producing a stream of matter that can be precisely controlled.

The result could be atomic-sized machines and measuring instruments, built to tolerances never before possible. Electronic circuits could be manufactured in which each "wire" consisted of a line of atoms - allowing super-miniaturisation a thousand times more compact than is now possible. It will also increase our understanding of the "quantum world" of individual atoms.

An experiment last November at the Massachusetts Institute of Technology (MIT), in Boston, produced a pulse of atoms at temperatures close to absolute zero (-273C) which behaved as though they were a single "superatom". Physicists call this a "Bose-Einstein condensate" - a state of matter which was only discovered in July 1995.

By cooling the atoms until their random heat energy was removed, the scientists produced particles which were locked into the same energy state, like a resonating solid. "It's very like a laser source," said Professor Keith Burnett, of the physics department at Oxford University, who has been working with the team at MIT on the theory of the system. "You can then control the atoms very precisely: they all come out in step, moving in exactly the same way. You could aim the beam where you want: it would be the ultimate printer."

Professor Burnett predicts that future versions of the system will be used for manufacturing in the 21st century, and for studying the boundary between the quantum world - in which matter and light can behave like waves and particles - and the macroscopic world, which we experience.

The latest work is reported in yesterday's edition of the journal Physical Review Letters, and also in this week's Science. "It's fantastic. It's really one of the most exciting things in atomic physics that I've seen in the last 10 years," said John Doyle, a professor at Harvard University.

Professor Burnett said: "My feeling is that this will evolve to be something of considerable interest. At the moment we can only see the obvious applications, like the `printer' idea. But it will also amplify our understanding of what we can do. We will become quantum engineers."