Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Imaging Electron Pairing in a Simple Magnetic Superconductor: Findings and resulting theory could reveal mechanism behind zero-energy-loss current-carrying capability

Click on the image to download a high-resolution version. The height above the plane of this diagram represents the energy required to break a superconducting pair of electrons into separate heavy fermions traveling in different directions (as determined from the quasiparticle scattering patterns). The maximum height is at the locations predicted if the "glue" holding the electron pairs together is magnetism.
Click on the image to download a high-resolution version. The height above the plane of this diagram represents the energy required to break a superconducting pair of electrons into separate heavy fermions traveling in different directions (as determined from the quasiparticle scattering patterns). The maximum height is at the locations predicted if the "glue" holding the electron pairs together is magnetism.

Abstract:
In the search for understanding how some magnetic materials can be transformed to carry electric current with no energy loss, scientists at the U.S. Department of Energy's Brookhaven National Laboratory, Cornell University, and collaborators have made an important advance: Using an experimental technique they developed to measure the energy required for electrons to pair up and how that energy varies with direction, they've identified the factors needed for magnetically mediated superconductivity-as well as those that aren't.

Imaging Electron Pairing in a Simple Magnetic Superconductor: Findings and resulting theory could reveal mechanism behind zero-energy-loss current-carrying capability

Upton, NY | Posted on July 14th, 2013

"Our measurements distinguish energy levels as small as one ten-thousandth the energy of a single photon of light-an unprecedented level of precision for electronic matter visualization," said Séamus Davis, Senior Physicist at Brookhaven the J.G. White Distinguished Professor of Physical Sciences at Cornell, who led the research described in Nature Physics. "This precision was essential to writing down the mathematical equations of a theory that should help us discover the mechanism of magnetic superconductivity, and make it possible to search for or design materials for zero-loss energy applications."

The material Davis and his collaborators studied was discovered in part by Brookhaven physicist Cedomir Petrovic ten years ago, when he was a graduate student working at the National High Magnetic Field Laboratory. It's a compound of cerium, cobalt, and indium that many believe may be the simplest form of an unconventional superconductor-one that doesn't rely on vibrations of its crystal lattice to pair up current-carrying electrons. Unlike conventional superconductors employing that mechanism, which must be chilled to near absolute zero (-273 degrees Celsius) to operate, many unconventional superconductors operate at higher temperatures-as high as -130°C. Figuring out what makes electrons pair in these so-called high-temperature superconductors could one day lead to room-temperature varieties that would transform our energy landscape.

The main benefit of CeCoIn5, which has a chilly operating temperature (-271°C), is that it can act as the "hydrogen atom" of magnetically mediated superconductors, Davis said-a test bed for developing theoretical descriptions of magnetic superconductivity the way hydrogen, the simplest atom, helped scientists derive mathematical equations for the quantum mechanical rules by which all atoms operate.

"Scientists have thought this material might be 'the one,' a compound that would give us access to the fundamentals of magnetic superconductivity in a controllable way," Davis said. "But we didn't have the tools to directly study the process of electron pairing. This paper announces the successful invention of the techniques and the first examination of how that material works to form a magnetic superconductor."

The method, called quasiparticle scattering interference, uses a spectroscopic imaging scanning tunneling microscope designed by Davis to measure the strength of the "glue" holding electron pairs together as a function of the direction in which they are moving. If magnetism is the true source of electron pairing, the scientists should find a specific directional dependence in the strength of the glue, because magnetism is highly directional (think of the north and south poles on a typical bar magnet). Electron pairs moving in one direction should be very strongly bound while in other directions the pairing should be non-existent, Davis explained.

To search for this effect, Davis group members Milan P. Allan and Freek Massee used samples of the material made by Petrovic. "To make these experiments work, you have to get the materials exactly right," Davis said. "Petrovic synthesized atomically perfect samples."

With the samples held in the microscope far below their superconducting temperature, the scientists sent in bursts of energy to break apart the electron pairs. The amount of energy it takes to break up the pair is known as the superconducting energy gap.

"When the pairs break up, the two electrons move off in opposite directions. When they hit an impurity in the sample, that makes a kind of interference, like waves scattering off a lighthouse," Davis explained. "We make movies of those standing waves. The interference patterns tell us the direction the electron was traveling for each energy level we send into the system, and how much energy it takes to break apart the pairs for each direction of travel."

The instrument uses the finest energy resolution for electronic matter visualization of any experiment ever achieved to tease out incredibly small energy differences-increments that are a tiny fraction of the energy of a single photon of light. The precision measurements revealed the directional dependence the scientists were looking for in the superconducting energy gap.

"Our job as scientists is to write down an equation and solve it to give a quantitative description of what we observed, and then use it to describe how magnetic superconductivity works and make and test predictions about how certain new materials will behave," Davis said.

One of the most important things the theory will do, he explained, will be to help separate the "epiphenomena," or side effects, from the true phenomena-the fundamental elements essential for superconductivity.

"Once you know the fundamental issues, which is what these studies reveal, it greatly enhances the probability of discovering a new material with the correct characteristics because you know what you are looking for-and you know what to avoid. We are very enthusiastic that we will be able to provide the theoretical tools for identifying the stuff to avoid when trying to make magnetic superconductors with improved properties," Davis said.

Davis and Petrovic worked with additional collaborators at Brookhaven, Cornell, and St. Andrews. The research was funded by the DOE Office of Science and the U.K. Engineering and Physical Sciences Research Council.

DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

####

About Brookhaven National Laboratory
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 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 (www.bnl.gov/newsroom) or follow Brookhaven Lab on Twitter (twitter.com/Brookhav
enLab).

For more information, please click here

Contacts:
Karen McNulty Walsh
(631) 344-8350

or
Peter Genzer
(631) 344-3174

Copyright © Brookhaven National Laboratory

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Scientific Paper: "Imaging Cooper pairing of heavy fermions in CeCoIn5"

Related News Press

News and information

Nanometrics to Announce Second Quarter Financial Results on July 30, 2019 July 17th, 2019

Breakthrough material could lead to cheaper, more widespread solar panels and electronics July 16th, 2019

Caught in the act: Images capture molecular motions in real time July 15th, 2019

NUS ‘smart’ textiles boost connectivity between wearable sensors by 1,000 times: Metamaterials are incorporated into conventional clothing to dramatically improve signal strength between electronic devices, allowing for new applications July 15th, 2019

An 'EpiPen' for spinal cord injuries July 12th, 2019

Laboratories

Caught in the act: Images capture molecular motions in real time July 15th, 2019

The best of both worlds: how to solve real problems on modern quantum computers July 12th, 2019

Research Reveals Exotic Quantum States in Double-Layer Graphene: Findings shed new light on the nature of electron interactions in quantum systems and establish a potential new platform for future quantum computers June 26th, 2019

Physics

Strange warping geometry helps to push scientific boundaries July 12th, 2019

Spontaneous synchronisation achieved at the nanoscale July 4th, 2019

New study shows nanoscale pendulum coupling July 3rd, 2019

Can break junction techniques still offer quantitative information at single-molecule level June 18th, 2019

Mysterious Majorana quasiparticle is now closer to being controlled for quantum computing: Princeton researchers detect a robust Majorana quasiparticle and show how it can be turned on and off June 14th, 2019

Superconductivity

Researchers report new understanding of thermoelectric materials: Discovery leads to promising new materials for converting waste heat to power June 21st, 2019

Perfect diamagnetism observation of high-temperature superconductivity in compressed H2S June 14th, 2019

Govt.-Legislation/Regulation/Funding/Policy

Caught in the act: Images capture molecular motions in real time July 15th, 2019

An 'EpiPen' for spinal cord injuries July 12th, 2019

The best of both worlds: how to solve real problems on modern quantum computers July 12th, 2019

What happens when you explode a chemical bond? Attosecond laser technique yields movies of chemical bond dissociation July 12th, 2019

Discoveries

Breakthrough material could lead to cheaper, more widespread solar panels and electronics July 16th, 2019

Caught in the act: Images capture molecular motions in real time July 15th, 2019

NUS ‘smart’ textiles boost connectivity between wearable sensors by 1,000 times: Metamaterials are incorporated into conventional clothing to dramatically improve signal strength between electronic devices, allowing for new applications July 15th, 2019

Strange warping geometry helps to push scientific boundaries July 12th, 2019

Materials/Metamaterials

Breakthrough material could lead to cheaper, more widespread solar panels and electronics July 16th, 2019

NUS ‘smart’ textiles boost connectivity between wearable sensors by 1,000 times: Metamaterials are incorporated into conventional clothing to dramatically improve signal strength between electronic devices, allowing for new applications July 15th, 2019

Strange warping geometry helps to push scientific boundaries July 12th, 2019

Experiments show dramatic increase in solar cell output: Method for collecting two electrons from each photon could break through theoretical solar-cell efficiency limit July 5th, 2019

Announcements

Nanometrics to Announce Second Quarter Financial Results on July 30, 2019 July 17th, 2019

Breakthrough material could lead to cheaper, more widespread solar panels and electronics July 16th, 2019

Caught in the act: Images capture molecular motions in real time July 15th, 2019

NUS ‘smart’ textiles boost connectivity between wearable sensors by 1,000 times: Metamaterials are incorporated into conventional clothing to dramatically improve signal strength between electronic devices, allowing for new applications July 15th, 2019

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Breakthrough material could lead to cheaper, more widespread solar panels and electronics July 16th, 2019

Caught in the act: Images capture molecular motions in real time July 15th, 2019

NUS ‘smart’ textiles boost connectivity between wearable sensors by 1,000 times: Metamaterials are incorporated into conventional clothing to dramatically improve signal strength between electronic devices, allowing for new applications July 15th, 2019

An 'EpiPen' for spinal cord injuries July 12th, 2019

Research partnerships

The best of both worlds: how to solve real problems on modern quantum computers July 12th, 2019

Sheaths drive powerful new artificial muscles July 11th, 2019

Activity of fuel cell catalysts doubled: Modelling leads to the optimum size for platinum fuel cell catalysts July 5th, 2019

Spontaneous synchronisation achieved at the nanoscale July 4th, 2019

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project