Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Laser-trapping of rare element gets unexpected assist

03.05.2007
Argonne researchers have successfully laser-cooled and trapped atoms of radium — the first time this rare element has been captured in a magneto-optical trap — with an assist from an unexpected source.

The group of physicists was attempting to trap the rare, radioactive element for studies of time-reversal violation, explained Argonne Compton Postdoctoral Fellow Jeffrey Guest of Argonne's Physics Division. Finding examples of this effect has implications for physics beyond the Standard Model and for explaining why the Big Bang yielded an imbalance between matter and antimatter in the universe.

Starting with less than a millionth of a gram of radium, the scientists vaporized, laser-cooled and captured the radium atoms in a magneto-optical trap. "This is the first time this rare element has been laser-cooled and trapped," Guest said. "It is the heaviest atom and only the second element with no stable isotopes — after francium — laser-trapped so far. It was particularly challenging to trap radium because quantities are scarce, and the atomic structure is not well studied and understood."

Radium atoms were slowed to a crawl and captured with magnetic fields and laser beams tuned near the atoms' resonant frequency. Future experiments will probe the cold radium atoms with lasers as they spin in place in a large electric field. The atoms will precess — wobble about their axes like tops winding down — as they spin. The frequency of this precession may reveal a slight offset between the negative and positive charge within the atom along its spin axis, a signature of time-reversal violation.

"Because their nuclei are egg-shaped, radium nuclei should be very sensitive to the time-reversal effects we want to investigate," Guest said. "However, radium is difficult to work with. Atoms tend to drift out of the trap, and because of radium's chemistry, it would stick to the walls of the vacuum chamber."

However, researchers were surprised to find the radium atoms were staying put much longer than expected. "We were surprised to discover that room temperature blackbody radiation actually played a pivotal and supportive role," Guest said.

Blackbody radiation is essentially heat; in this case, infrared radiation coming from the room-temperature walls of the apparatus. It's often a nuisance for experiments in physics, causing heating, contributing to background noise and scrambling quantum phases. However, when the radium atoms fell into metastable atomic states— in which the atoms could no longer “see” the trapping lasers — during the laser-cooling, the blackbody radiation added enough energy to the atoms to "recycle" them back to a configuration in which they could “see” the lasers again. This allowed the lasers to do their work and hold the atoms in place.

"This mechanism may be helpful in trapping other atoms with complex structure," Guest said.

The current effort in the laboratory is focused on adding a dedicated measurement apparatus to the experiment to begin the search for evidence of time-reversal asymmetry. Experiments with radium nuclei will begin in earnest.

A report on this achievement was recently published — and marked as a “suggestion” by the editors — in Physical Review Letters (PRL 98, 093001 (2007)). It was also featured in the American Institute of Physics Physics News Update Feb. 20.

Physics Division researchers on this project include Guest, Nick Scielzo (now at Lawrence Livermore National Laboratory), Jin Wang, Zheng-Tian Lu, Roy Holt, Irshad Ahmad and Dave Potterveld, with Kevin Bailey and Thomas O'Connor providing engineering support. John Greene of Argonne's Physics Division and Del Bowers of Argonne's Chemical Engineering Division prepared the radium samples. Health Physics support was supplied by Marian Williams of Argonne's ESH/QA Oversight Division.

The nation's first national laboratory, Argonne National Laboratory conducts basic and applied scientific research across a wide spectrum of disciplines, ranging from high-energy physics to climatology and biotechnology. Since 1990, Argonne has worked with more than 600 companies and numerous federal agencies and other organizations to help advance America's scientific leadership and prepare the nation for the future. Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

For more information, please contact Sylvia Carson (630/252-5510 or scarson@anl.gov) at Argonne.

Sylvia Carson | EurekAlert!
Further information:
http://www.anl.gov

More articles from Physics and Astronomy:

nachricht Quantum optical sensor for the first time tested in space – with a laser system from Berlin
23.01.2017 | Ferdinand-Braun-Institut Leibniz-Institut für Höchstfrequenztechnik

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

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: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

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...

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

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

Quantum optical sensor for the first time tested in space – with a laser system from Berlin

23.01.2017 | Physics and Astronomy

The interactome of infected neural cells reveals new therapeutic targets for Zika

23.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>