Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Superconductivity: Which one of these is not like the other?

15.07.2009
APS Physics this Week: Iron-based superconductors

Superconductivity appears to rely on very different mechanisms in two varieties of iron-based superconductors. The insight comes from research groups that are making bold statements about the correct description of superconductivity in iron-based compounds in two papers about to be published in journals of the American Physical Society.

The 2008 discovery of high-temperature superconductivity in iron-based compounds has led to a flood of research in the past year. As the literature mounts on these materials, which superconduct at temperatures as high as 55 K, two key questions are emerging: Is the origin of superconductivity in all of the iron-based compounds the same and are these materials similar to the copper oxide-based high-temperature superconductors (commonly known as cuprates), which physicists have studied for nearly twenty years but are still unable to explain with a complete theory?

These questions are addressed separately in two papers highlighted in the July 13 issue of Physics. A collaboration between scientists at Lawrence Berkeley National Lab, the SLAC National Accelerator Laboratory, Stanford University and institutions in Switzerland, China, Mexico and the Netherlands reports in Physical Review B x-ray experiments indicating that, in iron-based superconductors that contain arsenic or phosphorous (called 'iron pnictides'), the electrons that ultimately pair to form the superconducting state behave differently than those in the cuprates. More specifically, while the electrons in the cuprates are strongly correlated – meaning the energy of one electron is tied to the energy of the others – the electrons in the iron-pnictide superconductors behave more like those of a normal metal in which the electrons do not (to first approximation) interact.

In a paper appearing in Physical Review Letters, scientists at Princeton, UC Berkeley and Shanghai Jiao Tong University in China present the first photoemission measurements on an iron-based superconductor that contains tellurium, Fe1+xTe. They argue the origin of superconductivity in this type of iron compound, which belongs to a class of materials called the iron-chalcogenides, has a different origin than in the arsenic and phosphorous containing iron-pnictides. In fact, the measurements suggest that superconductivity in the iron-chalcogenides may be more similar to that of the cuprates.

The statements put forth in these two articles are likely to influence the direction taken by physicists who work on the theory of iron-based superconductors. See the Viewpoint article in the July 13 issue of APS Physics to learn more.

About APS Physics:

APS Physics (physics.aps.org) publishes expert written commentaries and highlights of papers appearing in the journals of the American Physical Society. Here are some of the papers that will be featured in the next issue of APS Physics.

James Riordon | EurekAlert!
Further information:
http://physics.aps.org

More articles from Physics and Astronomy:

nachricht Researchers discover link between magnetic field strength and temperature
21.08.2018 | American Institute of Physics

nachricht Smallest transistor worldwide switches current with a single atom in solid electrolyte
17.08.2018 | Karlsruher Institut für Technologie (KIT)

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: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

Protein interaction helps Yersinia cause disease

21.08.2018 | Life Sciences

Biosensor allows real-time oxygen monitoring for 'organs-on-a-chip'

21.08.2018 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>