Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Superconductivity - Electrons in Single File Provide New Insights


A team at the University of Innsbruck, Austria has been successful in conducting electrons in metals along predetermined channels. This behaviour, observed for the first time in metals, provides important insights into the interactions of electrons - and on how the phenomenon of the current flow without any resistance loss, termed super-conductivity, can occur. Thereby this project aided by the Austrian Science Fund (FWF) combines fundamental research, at its best, with potential applications in the future.

High-temperature superconductors are ceramic materials that conduct electricity without resistance, and thus without loss, below a certain temperature. At higher temperatures, the behaviour rapidly changes and experiences resistance. Such discontinuous changes due to external influences are typical for the so-called "smart materials". Their discontinuous behaviour is closely linked with a mutual dependence of spatially confined electrons, giving rise to a commonly coordinated motion pattern. So far this dependence termed as correlation had been observed only in non-metals.

Electrons in Single File...

Now a team under Prof. Erminald Bertel, Institute of Physical Chemistry, University of Innsbruck, Austria, has for the first time succeeded in forcing the electrons in a metal as well into such a mutual dependence. For this purpose, the researchers first of all created nano-structures on the surface of metal single crystals, which are crystals with uniform lattice structure.

Prof. Bertel, the project director, explains: "Normally, the electrons in a metal spread in all three directions in space. But in metal single crystals, some of the electrons are confined to the surface and therefore can move only in two dimensions. Nano-structures can then further restrict their freedom of movement. To produce such structures, the surfaces of copper crystals for instance can be oxidised in such a way that free copper channels of 3 nanometres width lie between ridges of copper oxide. In these channels, the electrons can only move unidimensionally. Also on platinum crystals atom chains can be arranged to run parallel across the surface with approximately 0.8 nanometre spacing. Certain electrons can then only spread along these chains."

Once the electrons were forced into a controlled motion along the channels or chains, Professor Bertel’s team was able to observe something fascinating - depending on experimental conditions, the electrons move within the individual channels entirely independent of each other, i.e. incoherently, or they align their movements across all channels. In such a state of motion that is described as coherent, the electrons can no longer be assigned to individual channels, but are "de-localised".

... When the Temperature is Right

For a closer analysis of the states of the electrons, the researchers at Innsbruck also made use of photoelectron spectroscopy. In this method, the energetic distribution of electrons emitted from the surface due to light (photon) absorption is measured. Interestingly, the spectra showed that above a critical temperature, the electrons pass from a coherent into an incoherent state.

A completely similar temperature dependence of photoelectron spectra, however, is already known in superconductors, but was explained differently so far. Thus the observations of the Innsbruck team suggest that the superconductivity in ceramic superconductors is connected to a transition of electrons from an incoherent state into a coherent state.

Prof. Bertel: "The transport of electricity without loss due to electric resistance could mean a significant contribution to energy saving and to the solution of some environmental problems. But at present our comprehension of superconductivity does not allow the synthesis of superconductive materials that can afford a commercial use under economical conditions. Our team has achieved in adding a small chip to the mosaic, which brings us a little closer to such applications."

Prof. Erminald Bertel | alfa
Further information:

More articles from Physics and Astronomy:

nachricht OU-led team discovers rare, newborn tri-star system using ALMA
27.10.2016 | University of Oklahoma

nachricht First results of NSTX-U research operations
26.10.2016 | DOE/Princeton Plasma Physics Laboratory

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: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>