Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Quantum Chaos in Ultracold Gas Discovered


The team of Francesca Ferlaino, University of Innsbruck, discovered that even simple systems, such as neutral atoms, can possess chaotic behavior, which can be revealed using the tools of quantum mechanics. The ground-breaking research, published in the journal Nature, opens up new avenues to observe the interaction between quantum particles.

The team of Francesca Ferlaino, Institute for Experimental Physics of the University of Innsbruck, Austria, has experimentally shown chaotic behavior of particles in a quantum gas.

Even simple systems, such as neutral atoms, can possess chaotic behavior.

Photo: Erbium Team, University of Innsbruck

“For the first time we have been able to observe quantum chaos in the scattering behavior of ultracold atoms,” says an excited Ferlaino. The physicists used random matrix theory to confirm their results, thus asserting the universal character of this statistical theory.

Nobel laureate Eugene Wigner formulated random matrix theory to describe complex systems in the 1950s. Although interactions between neutrons with atomic nuclei were not well-known then, Wigner was able to reliably predict properties of complex spectra by using random matrices.

... more about:
»Erbium »Phone »Quantum »chaotic »gases »particles

Today random matrix theory is applied broadly not only in physics but also in number theory, wireless information technology and risk management models in finance to name only a few fields of application. In the Bohigas-Giannoni-Schmit conjecture random matrix theory has been connected to chaotic behavior in quantum mechanical systems.

Catalan physicist Oriol Bohigas, who passed away last year, can be considered the father of quantum chaos research. 

Chaos in the quantum world

To observe quantum chaos, the physicists in Innsbruck cool erbium atoms to a few hundred nanokelvin and load them in an optical dipole trap composed of laser beams. They then influence the scattering behavior of the particles by using a magnetic field.

After holding the atoms in the trap for 400 milliseconds, the researchers record the atom number remaining in the trap. Thus, the scientists are able to determine at which magnetic field two atoms are coupled to form a weakly-bound molecule.

At this magnetic field, so-called Fano-Feshbach resonances emerge. After varying the magnetic field in each experimental cycle and repeating the experiment 14,000 times, the physicists identified 200 resonances.

“We were fascinated by how many resonances of this type we found. This is unprecedented in the physics of ultracold quantum gases,” says Francesca Ferlaino’s team member Albert Frisch. To explain the high density of resonances, the researchers used statistical methods. By using Wigner‘s random matrix theory the scientists are able to show that different molecular levels are coupled. This has also been confirmed by computer simulations conducted by Svetlana Kotochigova’s research group at Temple University in Philadelphia, Pennsylvania, USA.

“The particular properties of erbium cause a highly complex coupling behavior between the particles, which can be described as chaotic,” explains Ferlaino. Erbium is relatively heavy and highly magnetic, which leads to anisotropic interaction between atoms. “The electron shell of these atoms do not resemble spherical shells but are highly deformed,” explains Albert Frisch.

“Therefore, the type of interaction between two erbium atoms is significantly different from other quantum gases that have been investigated so far.”

Studying chaos experimentally

In contrast to everyday speech, chaos does not mean disorder for the physicists but rather a well-ordered system that, due to its complexity, shows random behavior. Ferlaino is excited about their breakthrough:

“We have created an experiment that provides a controlled environment to study chaotic processes. We cannot characterize the behavior of single atoms in our experiment. However, by using statistical methods, we can describe the behavior of all particles.”

She compares the method with sociology, which studies the behavior of a bigger community of people, whereas psychology describes the relations between individuals. This work also provides new inroads to the investigation of ultracold gases and, thus, ultracold chemistry.” Ferlaino is convinced: “Our work represents a turning point in the world of ultracold gases.”

The experiment and statistical analysis were carried out at the Institute for Experimental Physics at the University of Innsbruck. Theoretical support was provided by John L. Bohn from the Joint Institute for Laboratory Astrophysics in Boulder, Colorado, USA and the team of Svetlana Kotochigova at Temple University in Philadelphia, Pennsylvania, USA. The Austrian researchers are supported by the Austrian Science Fund FWF and the European Research Council (ERC). 

Publication: Quantum Chaos in Ultracold Collisions of Erbium. Frisch A, Mark M, Aikawa K, and Ferlaino F, Bohn JL, Makrides C, Petrov A, and Kotochigova S. Nature 2014
DOI: 10.1038/nature13137 [arXiv:1312.1972v1,]

Univ.-Prof. Dr. Francesca Ferlaino
Institute for Experimental Physics
University of Innsbruck
Phone: +43 512 507 52440

Dr. Christian Flatz
Public Relations
University of Innsbruck
Phone: +43 512 507 32022

Dr. Christian Flatz | Universität Innsbruck

Further reports about: Erbium Phone Quantum chaotic gases particles

More articles from Physics and Astronomy:

nachricht Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

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: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>