Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Important step towards quantum computing: Metals at atomic scale


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

Prof. Dr. Michael Ruck
TU Dresden
Tel.: 0351 463 33244

Prof. Dr. Markus Morgenstern
II. Physikalisches Institut B
Tel. 0049 241 / 80-27076

Weitere Informationen:

Dr. Carola Langer | idw - Informationsdienst Wissenschaft

More articles from Physics and Astronomy:

nachricht Novel light sources made of 2D materials
28.10.2016 | Julius-Maximilians-Universität Würzburg

nachricht OU-led team discovers rare, newborn tri-star system using ALMA
27.10.2016 | University of Oklahoma

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: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

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...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

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...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Steering a fusion plasma toward stability

28.10.2016 | Power and Electrical Engineering

Bioluminescent sensor causes brain cells to glow in the dark

28.10.2016 | Life Sciences

Activation of 2 genes linked to development of atherosclerosis

28.10.2016 | Life Sciences

More VideoLinks >>>