Washington (PTI): Scientists have come up with a new design, which they claim can be used to make the world's most precise clock as small as a wristwatch.

Cesium atomic clocks are used to define the basic unit of time -- the second -- to co-ordinate and synchronise global timekeeping, GPS navigation systems, computers on the Internet and scientific equipment. But these devices, known as fountain clocks, are very large and technically very complex.

Now, an international team has claimed that a new class of atomic clocks of at least equivalent accuracy could be made much smaller and simpler just by trapping aluminium, gallium, cesium or rubidium atoms in a lattice of laser light operated at a specific "magic" wavelength.

According to the researchers from Nevada University in the US and the University of New South Wales in Australia, the relative compactness of the new design would be of benefit in many scientific and general applications, and could also offer better control over errors in existing fountain clocks.

"We have determined these magic wavelengths and theoretically the accuracy is at least competitive to that of the most precise clocks existing today. "The size of these 'micro-magic' clocks may be reduced eventually to the size of a wristwatch, although ancillary equipment in the first laboratory variants would be much larger than that.

"We can't make specific claims about its accuracy or size until it is actually made, although we believe it will be relatively tiny compared to fountain clocks," team member professor Victor Flambaum was quoted by the Physical Review Letters journal as saying.