Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

University of Texas physicists put the squeeze on atoms

05.01.2006


Physicists capture small numbers of atoms in laser traps



Like bakers measuring the exact same amount of flour every time they made bread, physicists at The University of Texas at Austin have used a laser trap to consistently capture and measure the same small number of atoms.

Dr. Mark Raizen, Sid W. Richardson Foundation Regents Chair in Physics, and his colleagues at the Center for Nonlinear Dynamics have been able to repeatedly capture as few as sixty atoms in a box made of lasers.


They report their work in the Dec. 30, 2005 issue of Physical Review Letters.

Raizen’s ability to measure atoms with great accuracy places scientists one step closer to assessing and controlling single atoms and realizing quantum computing. Quantum computers will use the power of atoms to store information and make ultra-fast calculations.

Raizen’s work is also the beginning of a new field--quantum atom statistics.

"Some work closes a chapter on a problem in science, and some work opens a new chapter," says Raizen. "I view this as opening a new chapter because the study of quantum statistics of atoms has enormous potential for future discoveries."

Raizen and his colleagues created what’s called a squeezed number state, where the number of atoms captured in a laser trap was held nearly constant. To reach the atomic number squeezing, the physicists made a box out of sheets of laser light. The laser box had no top--just four sides and a bottom--and held a fixed number of atoms like a cup holding ping-pong balls.

"Suppose we have a trap that works like a cup," explains Raizen, "and I start putting ping-pong balls in the cup. I reach a point where I can’t put any more balls in without them spilling over. So there’s a hard cut-off on the number that can fit in the cup. That’s the mechanism we use, only our cup is made out of light."

The other difference, of course, is that Raizen and his colleagues used atoms instead of balls.

In the reported set of experiments, a cloud of Rubidium-87 atoms was trapped and super-cooled into a Bose-Einstein condensate so that they would occupy the ground state of the trap. A Bose-Einstein condensate is a new state of matter that is reached near the absolute zero of temperature, -459.67 Fahrenheit, and typically holds about one million atoms.

To decrease the atom number to as few as sixty atoms, the researchers very slowly lowered the sides of their laser box, which was about two micrometers (two millionths of a meter) across, and the atoms fell out over the lip.

"Every time we lowered the lip a little more, some atoms left the box until finally we reached the level we were happy with and we counted," says Raizen.

The researchers were able to repeatedly trap and count close to the same number of atoms each time with great accuracy, and Raizen says these are "the first measurements of quantum atom statistics by counting atoms." The small remaining fluctuations in number could be accounted for by taking into account small changes in the laser box’s dimensions.

Raizen has dubbed the new concept of the Bose-Einstein condensate leaking out over the top of the trap "quantum evaporation," because the atoms escaped the laser trap like water molecules evaporating out of a glass.

Since the publication of the paper, Raizen says that he and his colleagues have been able to accurately measure and trap as few as twenty atoms. They are aiming for one or two by making the box even smaller.

Lee Clippard | EurekAlert!
Further information:
http://www.utexas.edu

More articles from Physics and Astronomy:

nachricht Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology

nachricht NASA team finds noxious ice cloud on saturn's moon titan
19.10.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>