Atomic clock can shrink by "magic"

The world's most precise clock - on which all time-keeping and navigation systems are based - might be made as small as a wristwatch with a new design proposed by an international team of physicists.

Cesium atomic clocks are presently 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. They employ magnets and lasers to hold in place a beam of cesium atoms passing through an intense field of microwave energy.

A new class of atomic clocks of at least equivalent accuracy could be made much smaller and simpler by trapping aluminium, gallium, cesium or rubidium atoms in a lattice of laser light operated at a specific "magic" wavelength, according to a new theory put forward by physicists at the University of Nevada, in the US, and the University of New South Wales.

"We have determined these magic wavelengths and theoretically the accuracy is at least competitive to that of the most precise clocks existing today," says theoretical physicist Scientia Professor Victor Flambaum who, along with colleague Dr Vladimir Dzuba, belongs to UNSW's School of Physics.

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Media contact: Bob Beale | 0411 705 435 | bbeale@science.unsw.edu.au