Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Electrons ’in limbo’ seen for first time

16.03.2006


Two recent papers by Pitt physicist offer a deeper understanding of how electrons behave on surfaces, with applications in electronics and energy



Hrvoje Petek, University of Pittsburgh professor of physics and codirector of Pitt’s Gertrude E. and John M. Petersen Institute of NanoScience and Engineering (PINSE), has published two papers in recent weeks that literally illuminate how electrons behave on various surfaces.

In the first paper, Petek and Miroslav Nyvlt of Charles University in Prague explored the properties of metals under intense light--a situation "where the classical physics of electron emission from metals emerges from its quantum roots," says Petek. They found that when light of a certain energy and intensity is shone onto a metal surface, a few electrons in the metal become stuck on the surface (that is, they are neither emitted from nor reabsorbed into the metal). As Petek puts it, the electrons are "in limbo."


These electrons undergo the process of "total internal reflection"--a process well known for light, but observed by Petek and Nyvlt for the first time in electrons.

These findings, published in the March 3 issue of Physical Review Letters (PRL), could lead to the ability to transmit electrons, without scattering, over larger distances than previously possible. For example, electrons on the surface of carbon nanotubes could be excited to make "very small and very fast" transistors, Petek says.

"We anticipate that these elusive electrons will provide exquisite probes for how photons and electrons interact with metal surfaces," he adds.

In Petek’s second paper, published in the current issue of Science, he and Pitt Professor of Chemistry Kenneth Jordan, a PINSE researcher, make new progress toward extracting hydrogen from water using titanium dioxide as a catalyst.

In a May 2005 Science paper, Petek and Jordan presented their findings on the properties of water on the surface of titanium dioxide. In their current experiment, they used methanol instead of water, because they discovered that excited electrons last longer in methanol than in water, allowing chemical reactions to be observed.

This research shows how protons in methanol molecules move in such a way that they control the reabsorption of electrons into the titanium dioxide. Such motion, correlated between protons and electrons, is needed to convert light into chemical energy on solid surfaces, as well as by light-harvesting proteins.

PINSE is an integrated, multidisciplinary organization that brings coherence to the University’s research efforts and resources in the fields of nanoscale science and engineering. More information about PINSE can be found at www.nano.pitt.edu.

The work for the PRL paper was performed at the Max Planck Institute of Microstructure Physics in Halle, Germany, where Petek was an Alexander von Humboldt Senior Scholar and Nyvlt was the group leader. Other authors on the paper are Francesco Bisio, now at the University of Genoa; Jirka Franta, now at Charles University; and Jurgen Kirschner, director of the Max Planck Institute.

Karen Hoffmann | EurekAlert!
Further information:
http://www.nano.pitt.edu
http://www.pitt.edu

More articles from Physics and Astronomy:

nachricht DGIST develops 20 times faster biosensor
24.04.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht New quantum liquid crystals may play role in future of computers
21.04.2017 | California Institute of Technology

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>