Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Observation of confinement phenomenon in condensed matter

30.11.2009
Force of interaction between magnetic particles grows stronger with increasing distance

An experiment has confirmed that spinons, particle-like magnetic excitations, can be confined in a magnetic insulator similar to the way elementary quarks are confined within individual protons and neutrons. The finding, in a well-described magnetic system, may offer new ways to explore Quantum Chromodynamics, the theory that describes the fundamental interactions of quarks.

The observations of spinon confinement were made at the Science and Technology Facilities Councils Rutherford Appleton Laboratory in the United Kingdom by an international team of physicists. The team realized serendipitously that a theory developed 12 years earlier by theoretical physicist Alexei Tsevelik, now at the U.S. Department of Energy's Brookhaven National Laboratory, and collaborators accurately predicted the current findings. Together, the scientists describe the theory and their new observations in the November 29th issue of Nature Physics.

"The concept of confinement is one of the central ideas in modern physics, being at the core of the theory of nuclear forces," Tsvelik said. "In certain systems, when constituent particles are bound together by an interaction whose strength increases with increasing particle separation, individual particles cannot exist in a free state and therefore can be observed only indirectly."

The most famous example of confinement is of quarks which are held together in protons and neutrons, for example, by the strong force, a force that grows stronger with increasing distance.

"It has been interesting for us that a similar situation of confinement can be modeled in condensed matter systems," Tsvelik said. "Instead of quarks being confined in protons and neutrons, we have other quantum entities that act just like particles -- elementary excitations of magnetic systems called spinons."

In the case of the current experiment, the spinons exist on parallel chains of copper-oxide separated by inert calcium. Spinons on individual chains are not confined, but as soon as two chains are brought together to form ladder-like arrangements, the inter-ladder interactions confine the spinons.

"That is, the spinons can appear now only in pairs and cannot fly away from each other too far," Tsvelik said. "The result of this confinement is a particle we call a magnon. It is like two quarks pairing up to form a meson."

The original theory paper published by Tsvelik and collaborators 12 years ago described the magnetic excitation spectrum of such a system in detail. The team performing the experiments at Rutherford observed a signature that fit that description.

"Now that we have an example of confinement in a condensed matter system, our next step is to check further predictions of the theory to make sure there are no unpleasant surprises," Tsvelik said. The scientists will also measure the responses in other compounds to see if they observe similar effects.

Tsvelik's research is funded by the DOE Office of Science.

Upon publication, the paper can be downloaded at: http://dx.doi.org/10.1038/NPHYS1462

The Science and Technology Facilities Council ensures the UK retains its leading place on the world stage by delivering world-class science; accessing and hosting international facilities; developing innovative technologies; and increasing the socio-economic impact of its research through effective knowledge exchange partnerships. The Council has a broad science portfolio including Astronomy, Particle Physics, Particle Astrophysics, Nuclear Physics, Space Science, Synchrotron Radiation, Neutron Sources and High Power Lasers. In addition the Council manages and operates three internationally renowned laboratories: The Rutherford Appleton Laboratory, Oxfordshire; The Daresbury Laboratory, Cheshire; and The UK Astronomy Technology Centre, Edinburgh. For more information, visit: http://www.stfc.ac.uk.

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry, and government researchers. Brookhaven is operated and managed for DOEs Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation of the State University of New York, for and on behalf of Stony Brook University, the largest academic user of Laboratory facilities; and Battelle Memorial Institute, a nonprofit, applied science and technology organization. Visit Brookhaven Lab's electronic newsroom for links, news archives, graphics, and more (http://www.bnl/gov/newsroom), or follow Brookhaven Lab on Twitter (http://twitter.com/BrookhavenLab).

Related Links

* Additional news release on this research from Helmholtz-Zentrum Berlin: http://www.bnl.gov/bnlweb/pubaf/pr/docs/PR-HZB.pdf

Karen McNulty Walsh | EurekAlert!
Further information:
http://www.stfc.ac.uk
http://www.bnl/gov/newsroom

More articles from Physics and Astronomy:

nachricht APEX takes a glimpse into the heart of darkness
25.05.2018 | Max-Planck-Institut für Radioastronomie

nachricht First chip-scale broadband optical system that can sense molecules in the mid-IR
24.05.2018 | Columbia University School of Engineering and Applied Science

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: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>