Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Desktop Device Generates and Traps Rare Ultracold Molecules

17.12.2007
Physicists at the University of Rochester have combined an atom-chiller with a molecule trap, creating for the first time a device that can generate and trap huge numbers of elusive-yet-valuable ultracold polar molecules.

Scientists believe ultracold polar molecules will allow them to create exotic artificial crystals and stable quantum computers.

"The neat thing about this technology is that it's a very simple, but highly efficient method," says Jan Kleinert, a doctoral physics student at the University of Rochester and designer of the new device. "It lets us produce huge quantities of these ultracold polar molecules, which opens so many doors for us."

The Thin WIre electroStatic Trap, or TWIST, is the first electrostatic polar molecule trap that works simultaneously with a magneto-optical atom trap. This means Kleinert can use the lasers of the magneto-optical trap, or MOT, to chill atoms to just a few millionths of a degree above absolute zero, then force the atoms to group into molecules, and instantaneously hold them in place with the electrostatic TWIST trap.

Traditionally, a complex process of creating and trapping is required to produce these molecules, akin to repeatedly emptying and refilling the ice cube trays in your freezer, says Kleinert. A MOT with a TWIST, however, can create and store the chilled molecules in one place, instantly—more like a refrigerator with an automatic icemaker.

While polar molecules are literally as common as water, and dozens of laboratories around the world can cool atoms to such extreme temperatures, creating an ultracold polar molecule is difficult. Ultracold atoms can combine into molecules, but since only one type of atom can usually be cooled at once, the molecules it makes are electrically symmetric, not polar. Physicists have to either chill regular polar molecules, or chill several types of atoms at the same time and force them to join into molecules. Both processes are so complex that Kleinert says only four laboratories in the world do them, and the yield of ultracold polar molecules until now has been very low.

The TWIST, developed with Kleinert's advisor, Nicholas P. Bigelow, Lee A. DuBridge Professor of Physics at the University of Rochester, makes the complex process much more efficient, and thus makes available many more of these molecules.

The secret to the TWIST is the precise thickness of the tungsten wires that loop around the molecule-production area. In Kleinert's design, atoms are chilled with the lasers of a MOT, which drains away the atoms' energy, chilling them to nearly 460 degrees Fahrenheit below zero.

So far, this is exactly the same as the traditional method, but Kleinert surrounds his target area with tungsten loops that create an electric field. The field has no effect on the chilled atoms, but as the atoms are grouped into polar molecules by a process called photoassociation, the new polar molecules, with a positive charge on one side and a negative charge on the other, are affected by the field.

The electric field has a gradient, and due to some of the strange properties of the quantum world, polar molecules tend to "slide down" that gradient, collecting in the center of the field. As a result, says Kleinert, the TWIST collects and holds the low-field seeking polar molecules but lets other unaffected particles, such as atoms or other molecules, simply drift away.

Those tungsten loops have to be thick enough that they can withstand the electrostatic forces they generate, but thin enough that they don't block the MOT laser initiating the cooling. After months of trial and error and a lot of burned-out tungsten wire, Kleinert found that wires just the width of a hair provided the perfect balance.

"The coldest molecules so far have been produced from MOTs, but until the TWIST came along, electric field trapping and MOTs just didn't go together," says Kleinert. "Now we can accumulate these polar molecules continuously, without switching from creation to storage and back again."

With a good supply of ultracold polar molecules, computer scientists would have a new tool with which to tackle the creation of quantum computers, says Kleinert.

Quantum computer scientists are attracted to ultracold particles because their temperatures reduce decoherence, a phenomenon where your system decays from the carefully prepared quantum configuration you started with, to a classical physics state, which loses all the advantages quantum computers hold.

Ultracold polar molecules in particular are especially attractive because their strong polarity allows them to interact with each other over much larger distances than other atomic particles, and the stronger the interaction between particles, the faster a quantum computer can perform certain operations.

Ultracold polar molecules may even allow scientists to venture into an unknown quarter of the Standard Model of Physics—the size of the electron, says Kleinert. The answer to whether the electron has a definite size or is just a dimensionless point in space could support the Standard Model, or support one of the many alternate models. Trying to approximate the electron's size would likely require ultracold polar molecules, which can have 100 times the sensitivity of simple ultracold atoms. That difference could be enough to make a definitive measurement supporting or chipping away at the Standard Model altogether.

About the University of Rochester
The University of Rochester (www.rochester.edu) is one of the nation's leading private universities. Located in Rochester, N.Y., the University gives students exceptional opportunities for interdisciplinary study and close collaboration with faculty through its unique cluster-based curriculum. Its College of Arts, Sciences, and Engineering is complemented by the Eastman School of Music, Simon School of Business, Warner School of Education, Laboratory for Laser Energetics, Schools of Medicine and Nursing, and the Memorial Art Gallery.

Jonathan Sherwood | EurekAlert!
Further information:
http://www.rochester.edu

More articles from Physics and Astronomy:

nachricht First direct observation and measurement of ultra-fast moving vortices in superconductors
20.07.2017 | The Hebrew University of Jerusalem

nachricht Manipulating Electron Spins Without Loss of Information
19.07.2017 | Universität Basel

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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>