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
Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)
Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences