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 Physicists discover that lithium oxide on tokamak walls can improve plasma performance
22.05.2017 | DOE/Princeton Plasma Physics Laboratory

nachricht Experts explain origins of topographic relief on Earth, Mars and Titan
22.05.2017 | City College of New York

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: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

Im Focus: Hydrogen Bonds Directly Detected for the First Time

For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.

Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

Media accreditation opens for historic year at European Health Forum Gastein

16.05.2017 | Event News

 
Latest News

New approach to revolutionize the production of molecular hydrogen

22.05.2017 | Materials Sciences

Scientists enlist engineered protein to battle the MERS virus

22.05.2017 | Life Sciences

Experts explain origins of topographic relief on Earth, Mars and Titan

22.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>