Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Feat of experimental acrobatics leads to first synthesis of ultracold molecules

04.04.2005


Achievement could benefit fields of superchemistry, quantum computing



A research team that in 2003 created an exotic new form of matter has now shown for the first time how to arrange that matter into complex molecules.

The experiments--conducted by Cheng Chin, now at the University of Chicago, and his colleagues under the leadership of Rudolf Grimm at Innsbruck University in Austria--may lead to a better scientific understanding of superconductivity and advance a growing new field called superchemistry. In the long term, they may also provide a strategy that could aid the development of quantum computers. "In this field, it’s hard to predict what’s going to happen, because none of this was possible before 2003," said Chin, an Assistant Professor in Physics. Chin, Grimm and five colleagues will report their findings in a future issue of journal Physical Review Letters.


The new form of matter that the Innsbruck University team produced in 2003 is called a Fermion superfluid, which exists only at temperatures hundreds of degrees below zero. Superfluids exhibit characteristics distinctively different from the solids, liquids and gases that dominate everyday life. Most notably, superfluids can flow ceaselessly without any energy loss whatsoever. Science magazine named this work one of the top 10 breakthroughs of 2004.

In creating the Fermion superfluid, the team extended the work that earned the Nobel Prize in Physics for Eric Cornell, Wolfgang Ketterle and Carl Wieman in 2001. Those scientists had succeeded in creating the first Bose-Einstein condensate. Building on the work of Satyendra Nath Bose, Albert Einstein predicted in the 1920s that a special state of matter would form when a group of atoms collapsed into their lowest energy state. In this state now named for them, all of the atoms behave as if they are all one giant atom.

Cornell, Ketterle and Wieman created their Bose-Einstein condensate out of bosons, one of the two major categories of subatomic particles. Bosons carry force, while the other category of particles, fermions, comprise matter. Chin and the Innsbruck team showed in 2003 that, with some difficulty, fermions--in this case, lithium atoms--also can be coaxed into a Bose-Einstein condensate.

"Atoms themselves cannot become condensed. They are not bosons," Chin said. "But once they are paired they become bosons, and you can go to this superfluid state."

The laws of quantum mechanics forbid fermions from condensing. Chin and his colleagues used a technique called Feshbach resonance to bind two atoms into a simple molecule that behaves like a boson. The process is carried out in a magnetic field and resembles the type of electron pairing that causes superconductivity--the unimpeded flow of electricity at temperatures near absolute zero (minus 459.6 degrees Fahrenheit)--in solids.

This type of electron pairing is called Cooper pairing. Cooper pairings are the long-distance marriages of the subatomic world, where electrons are bonded at distances far greater than usual. "We have discovered a handle to adjust the interactions between atoms and between molecules, which allows us to synthesize complex quantum objects," Chin said.

Approximately two years ago, the Innsbruck scientists found a deep and unexpected connection between Bose-Einstein condensates and the bonding of Cooper pairs. They learned that they could use a pair of atoms to simulate the electrons of a Cooper pair. And more importantly, they could control the interactions of the atoms.

In their latest achievement, Chin and his colleagues have learned how to use Feshbach resonance as the control that binds the simple molecules made of cesium atoms into even larger clusters at temperatures near absolute zero.

"Since 2003, the controlled synthesis of simple molecules made of two atoms has opened up new frontiers in the field of ultracold quantum gases," said Rudolf Grimm, a professor of experimental physics at Innsbruck University and a co-author of the Letters article. Their present work now shows that ultracold simple molecules can be merged to form more complex objects consisting of four atoms, he said.

An important feature of this synthesis process is its tenability, Chin said. "In a magnetic field you can experimentally adjust it to any value, so we can control the process."

The synthesis of ultracold molecules is so new, it is difficult to predict potential applications, Chin said. But it puts a new field called superchemistry on a firm experimental footing. In superchemistry, scientists are able to precisely control the pairings and interactions of the atoms and molecules in Bose-Einstein condensates.

"We are physicists, but now our field’s starting to overlap with chemistry," Chin said.

As ultracold molecules are synthesized into complex quantum objects, phenomena hidden at the subatomic scale will now become visible almost to the naked eye. "These objects may open up completely new possibilities to study the rich quantum physics of few-body objects, including chemical reactions in the quantum world," Grimm said.

Control of quantum objects may ultimately lead to the realization of a quantum computer, Chin said. Although possibly still decades from fruition, a quantum computer would work much faster than today’s computers. The idea would be to use atoms in ultracold gas as bits, the basic units of information storage on a computer, with Feshbach resonance controlling their interactions to perform computations.

Chin now is setting up his laboratory at the University of Chicago and plans to continue studying quantum manipulation and computation based on cold atoms and molecules in collaboration with Grimm’s Innsbruck team.

"Based on the speed of progress in this field, I think there probably will be more surprises," Chin said.

Steve Koppes | EurekAlert!
Further information:
http://www.uchicago.edu

More articles from Physics and Astronomy:

nachricht Tune your radio: galaxies sing while forming stars
21.02.2017 | Max-Planck-Institut für Radioastronomie

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>