Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Electrons set free

04.04.2011
Free-floating electrons on top of liquid helium yield insights into their transport behavior

The multibillion dollar computer industry hinges on the ability to efficiently pass an electric current through a material. However, in any electronic device such as a computer transistor, the influence of the materials atom’s inevitably masks the interactions between the electrons.

Using a custom-designed system, a research team from the RIKEN Advanced Science Institute, Wako, in collaboration with colleagues from the University of Konstanz, Germany, has completed the first study of the transport of single floating electrons free of external influences[1].

Trapping electrons outside of matter and keeping them in order is difficult, but liquid helium is ideally suited to the task. Electrostatic charges in the liquid can attract electrons towards its surface but, owing to a lack of energy, the electrons cannot penetrate the surface and enter the liquid. Instead, caught between these competing influences, the electrons hover above the liquid helium, forming a two-dimensional electron system. “This is a unique system for studying the fundamental properties of electrons, as the electrostatic interactions between them are effectively unscreened,” says team member David Rees.

To measure the transport properties of this liquid-like system of electrons, the researchers fabricated a channel on the surface of a silicon chip that they filled with liquid helium. In one location, they physically narrowed the width of this channel and applied an electric field across the constriction, which provided further control over the effective channel width using electrostatic forces (Fig. 1).

When the channel width was sufficiently narrow, only one electron could pass through it at a time—the others were blocked by electrostatic repulsion. When the researchers slightly widened the channel by lowering the electric field across it, two electrons could pass through at the same time. Further widening would allow more electrons to pass through.

In addition to confirming the importance of electrostatic repulsions, these experiments open the door to further fundamental studies of electron behavior. If cooled to temperatures below one degree above absolute zero, the randomly floating electrons would arrange into a periodic and ordered array. This could provide the first opportunity to investigate the dynamics of a crystalline electron system, rather than a disordered liquid passing through a narrow constriction.

This model system of strongly interacting electrons may have other roles to play. According to Rees and team leader Kimitoshi Kono, if applied to other systems where the interactions between particles are strong, these findings could be used to understand the transport of particles such as ions in biological organisms.

The corresponding author for this highlight is based at the Low Temperature Physics Laboratory, RIKEN Advanced Science Institute

Journal information

[1] Rees, D.G., Kuroda, I., Marrache-Kikuchi, C.A., Höfer, M., Leiderer, P. & Kono, K. Point-contact transport properties of strongly correlated electrons on liquid helium. Physical Review Letters 106, 026803 (2011).

gro-pr | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6565
http://www.researchsea.com

More articles from Life Sciences:

nachricht Decoding the genome's cryptic language
27.02.2017 | University of California - San Diego

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

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...

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

New pop-up strategy inspired by cuts, not folds

27.02.2017 | Materials Sciences

Sandia uses confined nanoparticles to improve hydrogen storage materials performance

27.02.2017 | Interdisciplinary Research

Decoding the genome's cryptic language

27.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>