Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Delft University of Technology discovers how to control nanowires

13.06.2006
Jorden van Dam, researcher at the Kavli Institute of Nanoscience Delft, has succeeded in largely controlling the transportation of electrons in semiconductor nanowires. Van Dam moreover discovered how to observe a divergent type of supercurrent in these wires. Nanowires have superior electronic properties which in time could improve the quality of our electronics. On Tuesday, June 13, Van Dam will receive his PhD degree at Delft University of Technology based on this research.

During his PhD research, Jorden van Dam focused on semiconductor nanowires. These are extremely thin wires (1-100 nanometers thick) made of, for example, the material indiumarsenide, which has superior electronic properties. The integration of these high quality nanowires with the now commonly used silicium technology offers intriguing possibilities for improving our electronics in future. According to Van Dam, in recent years many possible applications for semiconductor nanowires have emerged, such as in lasers, transistors, LEDs and bio-chemical sensors. Philips is one of the companies that is conducting intensive research into the possibilities for semiconductor nanowires in specific applications.

Van Dam - who during his PhD research co-authored articles that were published in Nature and Science - was able to make a so-called quantum dot in a semiconductor nanowire (this is done at extremely low temperatures). These quantum dots can be regarded as artificial atoms and in the distant future will serve as building blocks for super-fast quantum computers.

In a quantum dot, a number of electrons can be ‘confined’. The magnificence of Van Dam's research is the total control he has managed to gain over the number of electrons that can be confined in a quantum dot. He can control this number by means of an externally introduced charge. A crucial factor for the extreme degree of control that Van Dam has achieved is the quality (for example the purity) of the nanowires, which were supplied by Philips. It is above all the quality of the material used (wires and electrodes) that was greatly improved during Van Dam's research.

The research also produced new physical observations. In the improved nanowires, Van Dam achieved for the first time the realisation and observation of a (theoretically already predicted) divergent type of supercurrent (a supercurrent is the current that occurs in superconductivity). In a quantum dot, the electrons normally pass through one by one. In superconductivity, the passage of electrons occurs in pairs. Van Dam, with the help of superconductor electrodes, has now achieved a supercurrent in the quantum dot, whereby the pairs of electrons pass through one by one.

Van Dam has also - under specific conditions - achieved a reversal in the direction of the supercurrent. He is able to control this reversal by varying the number of electrons confined in the quantum dot. With this, the Delft University of Technology researcher has achieved a largely controllable superconductor connection in semiconductor nanowires.

Frank Nuijens | alfa
Further information:
http://www.tudelft.nl/live/pagina.jsp?id=9eff0789-c0b6-4960-bdde-5cc4a00fb73b&lang=en
http://www.tudelft.nl

More articles from Physics and Astronomy:

nachricht MEMS chips get metatlenses
21.02.2018 | American Institute of Physics

nachricht International team publishes roadmap to enhance radioresistance for space colonization
21.02.2018 | Biogerontology Research Foundation

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: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Researchers invent tiny, light-powered wires to modulate brain's electrical signals

21.02.2018 | Life Sciences

The “Holy Grail” of peptide chemistry: Making peptide active agents available orally

21.02.2018 | Life Sciences

Atomic structure of ultrasound material not what anyone expected

21.02.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>