Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search


Otago physicists split and collide ultracold atom clouds

Tuesday 1 April 2014

Otago physicists split and collide ultracold atom clouds

University of Otago physicists have pushed the frontiers of quantum technology by developing a steerable ‘optical tweezers’ unit that uses intense laser beams to precisely split minute clouds of ultracold atoms and to smash them together.

The Otago researchers’ feat is set to enhance efforts to understand the mysterious ways that atoms interact at temperatures of less than a millionth of a degree above absolute zero. Its potential applications include new tools for probing microscopic structures or for sensors that can map minute variations in magnetic fields, says lead researcher Dr Niels Kjaergaard.

A description of their cutting-edge system is published in the April 1 issue of the US journal Optics Letters. It details an experiment in which the researchers used the technology to split a single ultracold cloud of rubidium atoms sequentially into 32 daughter clouds, spreading them out over nearly half a centimetre.

“This sort of precise control of these atoms is like being able to pull a delicate snowflake into two clean halves with your bare hands. It’s quite remarkable that we are able to manipulate such minute and fragile samples while moving them such a comparatively large distance,” Dr Kjaergaard says.

The experimental setup involves steering horizontal and vertical laser beams around through their interaction with precisely controlled travelling acoustic waves. These steerable laser beams confine and move the atoms. As well as splitting atom clouds, the system allows them to be collided.

“Tongue-in-cheek, we like to refer to our setup as the ‘Littlest Hadron Collider’. In some ways it’s the complete opposite of what is the world’s largest and most powerful particle collider, because instead of using extreme acceleration, we smash our atom clouds together at a pedestrian pace of up to a metre per second,” Kjaergaard says.

The steerable optical tweezers unit was constructed as part of Kris Roberts’ Honour’s thesis project in Dr Kjaergaard’s research group at the Jack Dodd Centre for Quantum Technology at the Department of Physics, while the control system for the acoustic waves was built by Master’s student Thomas McKellar.

“For researchers who are still students, these are quite notable achievements and I’m very proud of their work. It demonstrates the fantastic training opportunities that Otago can offer in its Physics programme,” Dr Kjaergaard says.

Kris is now a Master’s student in Dr Kjaergaard’s research group. The group’s work on the tweezers system is funded through a Marsden Fund of New Zealand grant.

QuickTime movies demonstrating capabilities of the optical tweezers unit:

• Splitting atomic clouds with laser tweezers

• 'Littlest hadron collider' at work

• The videos can also be viewed on this page:

© Scoop Media

Business Headlines | Sci-Tech Headlines


Land & Water Forum: Fourth Report On Water Management

The Land and Water Forum (LWF) today published its fourth report, outlining 60 new consensus recommendations for how New Zealand should improve its management of fresh water and calling on the Government to urgently adopt all of its recommendations from earlier reports. More>>



Welcome Home: Record High Migration Stokes 41-Year High Population Growth

New Zealand annual net migration hit a new high in October as more people arrived from than departed for Australia for the first time in more than 20 years. More>>


Citizens' Advice Bureau: Report Shows Desperate Housing Situation Throughout NZ

CAB's in-depth analysis of over 2000 client enquiries about emergency accommodation shows vulnerable families, pregnant women and children living in cars and garages, even after seeking assistance from the Ministry of Social Development and Housing New Zealand. More>>


Speaking For The Bees: Greens Call For Neonicotinoid Pesticide Ban

The National Government should ban the use of controversial pesticides called neonicotinoids after evidence has revealed that even at low doses they cause harm to bee populations, the Green Party said today. More>>


Get More From Scoop

Search Scoop  
Powered by Vodafone
NZ independent news