Featured Research

from universities, journals, and other organizations

Quasiparticle Behavior In Bose Quantum Liquids

Date:
April 7, 2005
Source:
Brookhaven National Laboratory
Summary:
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.

Physicist Igor Zaliznyak.
Credit: Photo courtesy of Brookhaven National Laboratory

LOS ANGELES, CA - 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.


Story Source:

The above story is based on materials provided by Brookhaven National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Brookhaven National Laboratory. "Quasiparticle Behavior In Bose Quantum Liquids." ScienceDaily. ScienceDaily, 7 April 2005. <www.sciencedaily.com/releases/2005/03/050326012711.htm>.
Brookhaven National Laboratory. (2005, April 7). Quasiparticle Behavior In Bose Quantum Liquids. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2005/03/050326012711.htm
Brookhaven National Laboratory. "Quasiparticle Behavior In Bose Quantum Liquids." ScienceDaily. www.sciencedaily.com/releases/2005/03/050326012711.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins