This was made possible by a new approach for producing ultraclean nanotubes. Moreover, the team of researchers, under the leadership of Spinoza winner Leo Kouwenhoven, discovered a new sort of tunnelling as a result of which electrons can fly straight through obstacles. The results of the research were published by Nature Nanotechnology on 5 April 2009.
A quantum dot can be viewed as a small ‘box’ which traps a controllable number of electrons. This box is coupled to one or more gate electrodes with which the number of electrons on the dot can be varied. The researchers developed a new technology to make extremely clean nanotube quantum dots. This makes it possible to capture a single electron in a nanotube. Moreover, the researchers succeeded in making the first highly-controllable single electron double dot.Controlling quantum dots
The researchers used silicon electrodes positioned close to the ultraclean nanotube to accurately control the number of electrons of the quantum dot. Three electrodes were used in the research, although more electrodes can be incorporated. The ultraclean tube ensures that no disruption occurs in the manipulation of the electrons.Tunnelling
In the case of normal tunnelling, electrons can only move from one quantum dot to another due to the tunnel coupling of the wave functions on both sides of the energy barrier within the double quantum dot. Researchers used the silicon gate electrodes to manipulate the barrier and observed tunnelling could become enhanced even though the barrier was increasing, as predicted in the Klein paradox. This method of tunnelling emphasises the close relationship between the physics of semiconductors, such as those in this research, and high-energy physics.
The research took place at the Kavli Institute for Nanoscience of Delft University of Technology. The first author of the article in Nature Nanotechnology is Gary Steele. Gary Steele, Georg Götz and Leo Kouwenhoven carried out the research with the aid of a grant from the Foundation for Fundamental Research on Matter (FOM) and NWO. Leo Kouwenhoven received the NWO/Spinoza Award in 2007.Nature publication
Gary Steele | EurekAlert!
Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory
SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute
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...
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...
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...
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...
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...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences