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 SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>