Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Important step towards quantum computing: Metals at atomic scale

03.03.2015

In the latest issue of the journal Nature Physics, German Scientists report that they could observe experimentally the current flow along channels at the crystal surfaces of topological insulators. The channels are less than one nanometer wide and extend along atomic steps of the crystal lattice. The scientists demonstrated also how these steps can be introduced in any arrangement.

Topological insulators are a hot topic in materials physics. The most prominent feature of these materials is that they act as both insulators and conductors, with their interior preventing the flow of electrical currents while their edges or surfaces allow the movement of charge.


Microscopic image of the topological insulator Bismuth-Rhodium-Iodine (Bi14Rh3I9). The engraved letters BiRhI act as artificially introduced steps at the crystal surface.

Photo: M. Morgenstern, RWTH Aachen


Crystal surface with a step acting as electron channel, left: Scanning Tunnel Microscopy image, right: Scanning Tunnel Spectroscopy

Photo: C. Pauly, RWTH Aachen

German Scientist from RWTH Aachen, Research Center Jülich, TU Dresden and of the Leibniz Institute for Solid State and Materials Research Dresden report that the current flow on the surface of a topological insulator is channeled along tiny paths, which have been theoretically calculated and experimentally observed.

Their work has been published in the issue from 2 March 2015 of the journal Nature Physics. There they show for Bismuth-Rhodium-Iodine that these channels are tied to one dimensional surface features and run along steps formed by the edges of atomic layers. Scanning tunneling spectroscopy reveals the electron channels to be continuous in both energy and space and less than one nanometer wide.

Due to the properties of topological insulators, electric current flows unimpeded within these channels while charge can barely move from one channel to another. In this way, the surface acts as a set of electric wires that is defined by the atomic steps at the crystals surface. The scientists demonstrated that the surface can be engraved in any arrangement, allowing channel networks to be patterned with nanometer precision.

The channeled current flow enables the transport of electrons while preventing the "scattering" typically associated with power consumption, in which electrons deviate from their trajectory. Thus, the resulting energy losses and heat generation are substantially diminished. These properties make topological insulators interesting for application in electronics. Furthermore, they are expected to enable novel types of information processing such as spintronics or quantum computation. However, the prerequisite for the development of new devices based on topological insulators is a profound understanding of these quantum phenomena. The recent publication marks a milestone in this direction.

During the last decade great effort are being made worldwide to investigate and to describe the transport in topological insulators. In 2013 the team of Professor Michael Ruck at TU Dresden has succeeded for the first time in growing single crystals of Bismuth-Rhodium-Iodine. Jointly with theoreticians from the Leibniz-Institute for Solid State and Materials Research Dresden they concluded that these crystals are topological insulators with electrical conducting channels. The recent experiments at RWTH Aachen and combined calculations in Dresden have now proved this hypothesis.

Publication: C. Pauly, B. Rasche, K. Koepernik, M. Liebmann, M. Pratzer, M. Richter, J. Kellner, M. Eschbach, B. Kaufmann, L. Plucinski, C. M. Schneider, M. Ruck, J. van den Brink, M. Morgenstern, Subnanometre-wide electron channels protected by topology, Nature Physics, March 2015, DOI 10.1038/nphys3264

Further information:

Prof. Dr. Jeroen van den Brink
IFW Dresden
Tel.: 0049 351 / 4659-400
j.van.den.brink@ifw-dresden.de

Prof. Dr. Michael Ruck
TU Dresden
Tel.: 0351 463 33244
Michael.ruck@tu-dresden.de

Prof. Dr. Markus Morgenstern
II. Physikalisches Institut B
Tel. 0049 241 / 80-27076
mmorgens@physik.rwth-aachen.de

Weitere Informationen:

http://www.ifw-dresden.de

Dr. Carola Langer | idw - Informationsdienst Wissenschaft

More articles from Physics and Astronomy:

nachricht SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>