Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Data processing: Tin for faster chips

28.10.2013
Intensive research is being conducted worldwide on a material that promises a revolution in data processing. For the first time ever, physicists have now produced this from a very simple substance.

To process and save data more and more quickly, to build even smaller and more powerful chips: these are the goals pursued by numerous research teams around the world.


Topological insulator: in a layer of tin, electrons separate automatically according to the orientation of their spin, symbolized by arrows.

(Markus R. Scholz/Arjun Kartha, http://arjunkarthaphotography.com)

For some years now, one special material class has been at the heart of their efforts, so-called topological insulators. Within these, electrons automatically separate according to their respective spin orientation, entirely without the use of electric or magnetic fields.

“This property is of far-reaching significance,” explains Professor Ralph Claessen from the Institute of Physics at the University of Würzburg: “If you apply electrical contacts to topological insulators, you can build circuits that transmit information coded with the spin orientation.” This new data transmission method is no longer based on the transport of electrical charges. It is therefore much faster and more reliable.

Why tin represents progress

Würzburg physicists have now, for the first time, succeeded in creating topological insulators made from tin, a simple and readily available material. “This makes production much easier because insulators like these have only ever been made from complex chemical compounds or hazardous materials,” says Claessen’s colleague Jörg Schäfer.

The physicists are presenting their findings in the journal “Physical Review Letters”. They have achieved their success as part of an international collaboration with teams from Switzerland and the USA as well as from the Jülich Research Center. At Würzburg’s Institute of Physics, Professor Laurens Molenkamp also works with topological insulators, and successfully so: a few years ago, motivated by theoretical predictions, he became the first person to verify the unusual properties of this material class in a series of experiments.

How the topological insulator came about

In the new experiments under Ralph Claessen’s chairmanship and Jörg Schäfer’s leadership, thin layers of tin were vapor-deposited onto a semiconductor substrate extremely slowly. An orderly crystal lattice of tin atoms formed, identical to that of diamond.

“Experiments then revealed that this layer has the unusual properties we were looking for: the spins of the electrons are sorted into two directions with opposite magnetic needle orientation, and the two groups move in opposite directions,” says Schäfer. This was proven with spin-resolved photoemission.

“This has enabled us to show, for the very first time, that the phenomenon of automatic spin separation also exists in a simple, elementary crystal lattice,” enthuses Schäfer. As a result, he believes that the production of practical topological insulators is now tantalizingly close. The new experiments were underpinned by theoretical observations that Würzburg physics professor Werner Hanke made with colleagues in Jülich.

Next steps for the physicists

Since the spin separation in the tin lattice itself can now be reliably produced, the physicists next want to explore and optimize the conductive behavior of complete structures with electrical contacts.

Initial demonstrations of spin transport in layers with topological materials have already worked at temperatures well below freezing. So, for practical application, a number of technological issues still need to be clarified, including the realization of circuits that work without cooling. For this purpose, the Würzburg physicists are now working intensively together, pooling their expertise in material production and analysis.

“Elemental Topological Insulator with Tunable Fermi Level: Strained alpha-Sn on InSb(001)”, A. Barfuss, L. Dudy, M. R. Scholz, H. Roth, P. Höpfner, C. Blumenstein, G. Landolt, J. H. Dil, N. C. Plumb, M. Radovic, A. Bostwick, E. Rotenberg, A. Fleszar, G. Bihlmayer, D. Wortmann, G. Li, W. Hanke, R. Claessen, and J. Schäfer, Physical Review Letters 111, 157205 (October 2013), DOI: 10.1103/PhysRevLett.111.157205

Contact

Dr. Jörg Schäfer, Institute of Physics, University of Würzburg, joerg.schaefer@physik.uni-wuerzburg.de

Robert Emmerich | Uni Würzburg
Further information:
http://www.uni-wuerzburg.de

More articles from Physics and Astronomy:

nachricht Applicability of dynamic facilitation theory to binary hard disk systems
08.12.2016 | Nagoya Institute of Technology

nachricht Will Earth still exist 5 billion years from now?
08.12.2016 | KU Leuven

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>