Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Quasiparticle Behavior in Bose Quantum Liquids

29.03.2005


Quasiparticles carry energy in condensed matter. In the world of quasiparticle physics, understanding when and how these energy carriers fail opens doors to another level of understanding, and can lead the way to many new and important theories. Scientists at the U. S. Department of Energy’s Brookhaven National Laboratory have discovered the failure point for the quasiparticle construct, the standard model of condensed matter physics. This could have far-reaching implications, for example, in the study of high-temperature superconductors, materials currently under intense scrutiny as a possible replacement for the conventional superconducting materials now used in many facets of everyday life.

At the March 2005 meeting of the American Physical Society, Brookhaven physicist Igor Zaliznyak will explain how he and his colleagues identified the “spectrum endpoint” in a Bose quantum spin liquid, the point at which the quasiparticles are no longer well-defined energy carriers. Zaliznyak will discuss his paper at 1:39 p.m. Friday, March 25, 2005, in Room 515B of the Los Angeles Convention Center.

“Although the quantum-liquid state has been studied for roughly a century, it continues to fascinate physicists,” Zaliznyak said. “We have demonstrated that at higher energies, the Bose quasiparticle description fails because of quasiparticle decay.”



The study of quasiparticles, which govern the properties of quantum liquids, was pioneered by Russian Nobel Prize winning-physicist L.D. Landau. There are two types of quasiparticles, Bose and Fermi, and physicists around the globe are exploring the properties of each type. The Brookhaven experiments, conducted using the triple-axis neutron spectrometer at the National Institutes of Standards and Technology, confirmed that in a particular Bose quantum spin liquid, quasiparticle decay leads to spectrum termination, as was predicted by Landau.

“Landau proposed that at some energy, the quasiparticle description breaks down, and in a generic form this has been known,” Zaliznyak said. “But the extent of the phenomenon and how it reveals itself in real materials hasn’t been clear. We have shown that at twice the minimum excitation energy, known as the spin gap, Bose quasiparticles cease to be defined at all and disappear.”

The Brookhaven experiments studied a quantum liquid found in systems composed of quantum spins in magnetic crystals, specifically an organo-metallic material known as PHCC. The scientists’ neutron scattering measurements demonstrate the occurrence of spectrum termination in the two-dimensional quantum spin liquid found in PHCC.

“When you attempt to create an excitation that is more than twice the gap rate, it’s possible that your excitation decays, “ Zaliznyak said. “In Bose quantum liquids, when decay processes like this become allowed, you can’t have quasiparticles.”

The research was funded by the Office of Basic Energy Sciences within the U.S. Department of Energy’s Office of Science, the National Science Foundation, and the Robert A. Welch Foundation.

Kay Cordtz | EurekAlert!
Further information:
http://www.bnl.gov

More articles from Physics and Astronomy:

nachricht Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials
17.01.2018 | Universität des Saarlandes

nachricht Black hole spin cranks-up radio volume
15.01.2018 | National Institutes of Natural Sciences

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: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Polymers Based on Boron?

18.01.2018 | Life Sciences

Bioengineered soft microfibers improve T-cell production

18.01.2018 | Life Sciences

World’s oldest known oxygen oasis discovered

18.01.2018 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>