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Atomic clock can shrink by "magic"
By Bob Beale
November 26, 2008
Professor Victor Flambaum
By Bob Beale
November 26, 2008
Professor Victor Flambaum
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 a
The relative compactness of the new design would be of benefit in many scientific and general applications and could offer better control over errors in existing fountain clocks, the researchers say in two papers in the journal Physical Review Letters.
Their proposal extends a recent realisation that trapping atoms in an optical lattice of laser light at a so-called "magic" wavelength - where the light beams mutually cancel out any perturbations they may cause - can be used to substantially improve the accuracy and stability of optical atomic clocks.
"We have determined these magic wavelengths and theoretically the accuracy is at least competitive to that of the most precise clocks existing today," says Scientia Professor Victor Flambaum, a member of the team who, with colleague Dr Vladimir Dzuba, is a theoretical physicist in the UNSW School of Physics.
"The size of these 'micro-magic' clocks might 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. But I would be very surprised if nobody made one. It's an intriguing new idea and we've had much interest in it from around the world."
The researchers have filed patent applications on the concept.
Media contacts:
Professor Victor Flambaum - E: v.flambaum@unsw
UNSW Faculty of Science: Bob Beale - E: bbeale@unsw.edu
