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 Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

nachricht What do Netflix, Google and planetary systems have in common?
02.12.2016 | University of Toronto

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: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>