Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Curved carbon for electronics of the future

24.01.2011
A new scientific discovery could have profound implications for nanoelectronic components.

Researchers from the Nano-Science Center at the Niels Bohr Institute, University of Copenhagen, in collaboration with Japanese researchers, have shown how electrons on thin tubes of graphite exhibit a unique interaction between their motion and their attached magnetic field – the so-called spin.

The discovery paves the way for unprecedented control over the spin of electrons and may have a big impact on applications for spin-based nanoelectronics. The results have been published in the prestigious journal Nature Physics.

Carbon is a wonderfully versatile element. It is a basic building block in living organisms, one of the most beautiful and hardest materials in the form of diamonds and is found in pencils as graphite. Carbon also has great potential as the foundation for computers of the future as components can be produced from flat, atom thin graphite layers, observed for the first time in the laboratory in 2004 – a discovery which elicited last year's Nobel Prize in Physics.

In addition to a charge all electrons have an attached magnetic field – a so-called spin. One can imagine that all electrons carry around a little bar magnet. The electron's spin has great potential as the basis for future computer chips, but this development has been hindered by the fact that the spin has proved difficult to control and measure.

In flat graphite layers the movement of the electrons do not affect the spin and the small bar magnets point in random directions. As a result, graphite was not an obvious candidate for spin based electronics at first.

New spin in curved carbon

"However, our results show that if the graphite layer is curved into a tube with a diameter of just a few nanometers, the spin of the individual electrons are suddenly strongly influenced by the motion of the electrons. When the electrons on the nanotube are further forced to move in simple circles around the tube the result is that all the spins turn in along the direction of the tube", explain the researchers Thomas Sand Jespersen and Kasper Grove-Rasmussen at the Nano-Science Center at the Niels Bohr Institute.

It has previously been assumed that this phenomenon could only happen in special cases of a single electron on a perfect carbon nanotube, floating freely in a vacuum – a situation that is very difficult to realize in reality. Now the researchers' results show that the alignment takes place in general cases with arbitrary numbers of electrons on carbon tubes with defects and impurities, which will always be present in realistic components.

The interaction between motion and spin was measured by sending a current through a nanotube, where the number of electrons can be individually controlled. The two Danish researchers explain that they have further demonstrated how you can control the strength of the effect or even turn it off entirely by choosing the right number of electrons. This opens up a whole range of new possibilities for the control of and application of the spin.

Unique Properties

In other materials, like gold for example, the motion of the electrons also have a strong influence on the direction of the spin, but as the motion is irregular, one cannot achieve control over the spin of the electrons. Carbon distinguishes itself once again from other materials by possessing entirely unique properties – properties that may be important for future nanoelectronics.

Nature Physics: http://dx.doi.org/ + 10.1038/NPHYS1880

For more information:

Thomas Sand Jespersen, postdoc, Nanophysics, Niels Bohr Institute, University of Copenhagen, +45 3532-0402, mobile: +45 2857-0164, tsand@fys.ku.dk

Kasper Grove-Rasmussen, postdoc, Nanophysics, Niels Bohr Institute, University of Copenhagen, +45 3532-0402, k_grove@fys.ku.dk

Gertie Skaarup | EurekAlert!
Further information:
http://www.nbi.dk

More articles from Physics and Astronomy:

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>