Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

One electron makes all the difference

13.02.2008
A research team from the department of condensed matter physics of the Universidad Autónoma de Madrid working in collaboration with the research group lead by professor Christian Schoenenberger at the Basilea university in Switzerland, have discovered that just an electron sets the conductive properties of a carbon nanotube.

Since their discovery in 1991, carbon nanotubes have continually fascinated physicists and chemists with their amazing electronic and mechanical properties.

These cylindrical molecules with a radius of a few Angstroms (1×10-10 meters) and with lengths of up to several micrometers (1×10-6 meters) have endless applications inside different scientific fields from nanoelectronics to material science, and are used by scientists to study a wide range of physical phenomena that only take place at a nanometric scale.

The combination of nanotubes and other materials form hybrid structures and these are of particular interest. For example, carbon nanotubes connected to superconductive electrodes (materials that offer no electrical resistance at low temperatures) are currently being used to study exotic physical phenomena like the Josephson Effect. This Nobel Prize winning discovery made by physicist Brian D. Josephson in 1973 consists of the almost magic effect of producing an electrical current in a superconductive junction without the application of a voltage.

In the last two three years several research groups have demonstrated that in a carbon nanotube held in between superconducting electrodes, the Josephson effect can be controlled at will, making possible a superconductive version of a transistor. This discovery has endless possibilities, most of which have barely started to be investigated.

A research group from the UAM working in collaboration with a research team lead by Christian Schoenenberger of Basilea University, has recently published an article in the Physical Review Letters, where a new phenomenon that takes place within these nanotube-superconductor structures has been described.

Demonstrating that carbon nanotubes truly are an endless supply of new physical phenomena, they have discovered that when a voltage is applied to these hybrid structures, the electric current that flows depends greatly on the number of electrons that are present at the nanotube, and furthermore, whether this number is even or odd has a drastic impact. This new transport phenomenon is caused by subtle interactions between the Spins (magnetic field produced by the electrons as they rotate) of the electrons in the carbon nanotubes - a characteristic which depends on their number and the conducting electrons in the superconductor.

Oficina de Cultura Científica | alfa
Further information:
http://dx.doi.org/10.1103/PhysRevLett.99.126602

More articles from Physics and Astronomy:

nachricht Hope to discover sure signs of life on Mars? New research says look for the element vanadium
22.09.2017 | University of Kansas

nachricht Calculating quietness
22.09.2017 | Forschungszentrum MATHEON ECMath

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: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>