Contact Information:
Karen McNulty Walsh
DOE/Brookhaven National Laboratory

Kredyty mieszkaniowe Kredyty mieszkaniowe

Sprawdź aktualny ranking najlepszych kredytów mieszkaniowych w Polsce - atrakcyjne kredytowanie nieruchomości. - Press Release Distribution
RSS - Press News Release
Add Press Release

Ultrathin copper-oxide layers behave like quantum spin liquid

Surprising discovery may offer clues to emergence of high-temperature superconductivity

( UPTON, NY - Magnetic studies of ultrathin slabs of copper-oxide materials reveal that at very low temperatures, the thinnest, isolated layers lose their long-range magnetic order and instead behave like a "quantum spin liquid" - a state of matter where the orientations of electron spins fluctuate wildly. This unexpected discovery by scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and collaborators at the Paul Scherrer Institute in Switzerland may offer support for the idea that this novel condensed state of matter is a precursor to the emergence of high-temperature superconductivity - the ability to carry current with no resistance.

The hope is that this research, just published online in Physical Review Letters*, will lead to a deeper understanding of the physics of high-temperature superconductivity and advance the quest for new and better superconductors for meeting the nation's and world's energy needs.

The idea of quantum spin liquids is credited to Nobel laureate Philip W. Anderson, who also proposed the possible link to the emergence of high-temperature superconductivity when copper-oxide, or "cuprate," materials are doped with mobile charge carriers - that is, when atoms supplying additional electrons or electron vacancies are added. However, some past experimental findings haven't supported this proposal: Without doping, lanthanum-copper-oxide, one of the most studied cuprates, shows a form of long-range magnetic order known as anti-ferromagnetism - where spin orientations on adjacent electrons alternately point in exactly opposite directions - even at room temperature. But the new Brookhaven Lab/Scherrer Institute experiments suggest a different picture when one looks at thin enough layers.

"The crystal structure of lanthanum-copper-oxide is layered; it consists of parallel copper-oxide and lanthanum-oxide sheets," explained Brookhaven physicist Ivan Bozovic, one of the lead authors on the paper. "The interaction among the spins within one copper-oxide plane is strong, while their interaction with the spins in the nearest copper-oxide plane (about 0.66 nanometers away) is ten thousand times weaker. Still, this weak interaction between layers may be sufficient to suppress fluctuations and stabilize the anti-ferromagnetic order."

The key to finding out if there was fluctuation-suppressing interaction among layers was to look for magnetic order in thinner films, with fewer layers and better insulation.

Bozovic used a specialized atomic-layer-by-layer molecular beam epitaxy method he's developed to assemble lanthanum-copper-oxide samples with varying numbers of layers. The layers were well separated and insulated to prevent any "crosstalk." The thickness was controlled with atomic precision and varied digitally, down to a single copper-oxide plane. This precision was critically important for the success of the experiment.

These unique samples were studied at the Paul Scherrer Institute by Elvezio Morenzoni and his team, who had developed an exquisite diagnostic technique called low-energy muon spin spectroscopy to detect and investigate magnetism in such ultrathin layers.

The magnetic measurements revealed that when the slabs contained four or more copper-oxide layers, they showed anti-ferromagnetic ordering - just like thick, bulk crystals of the same materials, and even up to the same temperature. However, thinner slabs that contained just one or two copper-oxide layers showed an unexpected result: "While the magnetic moments, or spins, were still present and had about the same magnitude, there was no long-range static anti-ferromagnetic order, not even on the scale of a few nanometers. Rather, the spins were fluctuating wildly, changing their direction very fast," Bozovic said.

Even more telling, this effect was stronger the lower the temperature of the sample. "That means these fluctuations could not be of thermal origin and must be of quantum origin - quantum objects fluctuate even at zero temperature," Bozovic explained.

"Altogether, this experiment indicates that once a copper-oxide plane is well isolated and not interacting with other such layers, it in fact seems to behave, at low temperature, like some sort of quantum spin liquid." Bozovic said. So perhaps the idea that high-temperature superconductivity emerges from this quantum spin liquid state could, after all, be true.

"We certainly need to do more experiments to test the implications of our discovery and how it relates to this theoretical prediction," Bozovic said.


This work was supported by the DOE Office of Science.

Media Contacts : Karen McNulty Walsh,, (631) 344-8350 or Peter Genzer,, (631) 344-3174

This release is also available at:

Related Links

*Scientific paper: Two-Dimensional Magnetic and Superconducting Phases in Metal-Insulator La2-xSrxCuO4 Superlattices Measured by Muon-Spin Rotation: Exploring the Superconducting Transition in Ultra Thin Films:

Fleeting Fluctuations in Superconductivity Disappear Close to Transition Temperature:

Giant Proximity Effect Enhances High-Temperature Superconductivity:

Pinning Down Superconductivity to a Single Layer:

Scientists Engineer Superconducting Thin Films:

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 DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation of State University of New York on behalf of Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

Visit Brookhaven Lab's electronic newsroom for links, news archives, graphics, and more at , or follow Brookhaven Lab on Twitter, .



Sexual Harassment in West Virginia Workplaces

Under federal and West Virginia state laws, you have the right to work free from gender discrimination or harassment. Most people know that sexual harassment is wrong, but they don't know exactly what the term means. Simply put, sexual harassment is -- according to Black's Law Dictionary -- "a type of employment discrimination consisting of verbal or physical abuse of a sexual nature." Admittedly, this is a somewhat vague definition. Fortunately, though, laws and court rulings have provided guidance to employers and employees alike as to what sorts of behaviors ...

An egalitarian Internet? Not so, UGA study says

Athens, Ga. – The Internet is often thought of as a forum that enables egalitarian communication among people from diverse backgrounds and political persuasions, but a University of Georgia study reveals that online discussion groups display the same hierarchical structure as other large social groups. "About 2 percent of those who start discussion threads attract about 50 percent of the replies," said study author Itai Himelboim, assistant professor in the UGA Grady College of Journalism and Mass Communication. "So although we have this wide range and diversity of ...

Clever tool use in parrots and crows

Clever tool use in parrots and crows
This release is available in German. The kea, a New Zealand parrot, and the New Caledonian crow are members of the two most intelligent avian families. Researchers from the Department of Cognitive Biology of the University of Vienna investigated their problem solving abilities as well as their innovative capacities. They are publishing two new studies – one in cooperation with members of the Behavioral Ecology Research Group in Oxford – in the scientific journals PLoS ONE and Biology Letters. Parrots and Corvids frequently astonish researchers investigating animal ...

Denial of Adjustment of Status and the 245(K) Controversy

The past two years have seen an increase in the rate of denial of applications for adjustment of status. With the denial of these applications, particularly employment-based adjustment of status, the USCIS is almost immediately issuing a Notice to Appear (NTA) in removal proceedings. With the USCIS sending almost all employment cases to the Nebraska Service Center (NSC), employers and their sponsored workers can almost expect to receive a Request for Evidence (RFE) from USCIS on the I-140, I-485 or both at some point during the protracted process. The USCIS is brazenly ...

U-M researchers find potential new way to fight sepsis

U-M researchers find potential new way to fight sepsis
ANN ARBOR, Mich. — By digging a little deeper, researchers may have found a potential target for reversing the deadly blood infection sepsis. Scientists at the University of Michigan Health System looked at microRNA, a type of RNA that does not code for a protein itself but that can regulate the expression of other genes and proteins. They found that by attacking the right microRNA they could influence a key trigger of inflammatory diseases such as sepsis. Traditionally, researchers have gone after a bigger target, attempting to find compounds that directly control ...

FY 2012 H-1B Visa Quota Opens April 1, 2011!

Yes, it's that time of year again: The H-1B visa quota for FY 2012 will finally open up on April 1, 2011, making 65,000 new H-1B visa numbers available for new employment beginning on October 1, 2011. Since the H-1B quota for the last several fiscal years has closed well before the next fiscal year commenced, thousands of applicants are already preparing their H-1B Petitions to be filed on or soon after April 1, 2011, which is the earliest date on which an employer may submit a new petition. Absent some extraordinary Congressional action, the recent trend of early-exhaustion ...

Prototype demonstrates success of advanced new energy technology

CORVALLIS, Ore. – With the completion of a successful prototype, engineers at Oregon State University have made a major step toward addressing one of the leading problems in energy use around the world today – the waste of half or more of the energy produced by cars, factories and power plants. New technology is being developed at OSU to capture and use the low-to-medium grade waste heat that's now going out the exhaust pipe of millions of automobiles, diesel generators, or being wasted by factories and electrical utilities. The potential cost savings, improved energy ...

Clients' Bill of Rights: 2011

Every year, I write hundreds of articles for the press dealing, in general terms, with new immigration laws, regulations and interpretations impacting hundreds of thousands of immigrants both inside and outside the US. Rather than start off this New Year with an article regarding new changes in the law or changing interpretations as to what can be done, legally, for clients in certain circumstances; I decided to publish an article about how things should be done, in practice, for clients seeking the highest quality legal representation. Clients should be aware that when ...

USDA-led consortium sequences genome of key wheat pathogen

This release is available in Spanish. A U.S. Department of Agriculture (USDA)-led consortium of scientists has fully sequenced the genome of the pathogen that causes the wheat disease known as septoria tritici blotch, which can cause significant yield losses. According to the International Maize and Wheat Improvement Center in Mexico, losses can reach as high as 50 percent if fungicides are not used to protect susceptible wheat lines. Thise disease is found in every wheat-growing area in the world, including the United States. The research, published in PLoS Genetics, ...

New substances added to HHS Report on Carcinogens

The U.S. Department of Health and Human Services today added eight substances to its Report on Carcinogens, a science-based document that identifies chemicals and biological agents that may put people at increased risk for cancer. The industrial chemical formaldehyde and a botanical known as aristolochic acids are listed as known human carcinogens. Six other substances – captafol, cobalt-tungsten carbide (in powder or hard metal form), certain inhalable glass wool fibers, o-nitrotoluene, riddelliine, and styrene – are added as substances that are reasonably anticipated ...


How your brain decides blame and punishment -- and how it can be changed

Uniquely human brain region enables punishment decisions

Pinpointing punishment

Chapman University publishes research on attractiveness and mating

E-cigarettes: Special issue from Nicotine & Tobacco Research

Placental problems in early pregnancy associated with 5-fold increased risk of OB & fetal disorders

UT study: Invasive brood parasites a threat to native bird species

Criminals acquire guns through social connections

Restoring ocean health

Report: Cancer remains leading cause of death in US Hispanics

Twin study suggests genetic factors contribute to insomnia in adults

To be fragrant or not: Why do some male hairstreak butterflies lack scent organs?

International team discovers natural defense against HIV

Bolivian biodiversity observatory takes its first steps

Choice of college major influences lifetime earnings more than simply getting a degree

Dominant strain of drug-resistant MRSA decreases in hospitals, but persists in community

Synthetic biology needs robust safety mechanisms before real world application

US defense agencies increase investment in federal synthetic biology research

Robots help to map England's only deep-water Marine Conservation Zone

Mayo researchers identify protein -- may predict who will respond to PD-1 immunotherapy for melanoma

How much water do US fracking operations really use?

New approach to mammograms could improve reliability

The influence of citizen science grows despite some resistance

Unlocking secrets of how fossils form

What happens on the molecular level when smog gets into the lungs?

Using ultrasound to clean medical instruments

Platinum and iron oxide working together get the job done

Tiny silica particles could be used to repair damaged teeth, research shows

A quantum lab for everyone

No way? Charity's logo may influence perception of food in package

[] Ultrathin copper-oxide layers behave like quantum spin liquid
Surprising discovery may offer clues to emergence of high-temperature superconductivity is a service of DragonFly Company. All Rights Reserved.
Issuers of news releases are solely responsible for the accuracy of their content.