Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First Confirmation of New Theory by Metamaterial

10.06.2020

Physicists in Würzburg have experimentally demonstrated a novel effect for the first time by exploiting topological metamaterials. They published their results in the journal Nature Physics.

Topological metamaterials are applied as a novel platform to explore and study extraordinary effects. Instead of using natural materials, researchers artificially arrange the constituents of a topological metamaterial in a regular structure.


A unit cell cutout of the circuit board, which was built to demonstrate the non-Hermitian skin effect, and the underlying theoretical non-Hermitian model.

Tobias Helbig, Tobias Hofmann


A current feed is imposed on the left side of a circuit with 20 unit cells realized by an external current source.

Tobias Helbig, Tobias Hofmann

Such an arrangement is analogous to a solid state in which the atoms form a crystal lattice. Usually, these platforms are used to simulate particular properties of solids in order to make them amenable to experimental investigation.

Physicists at Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany, perform research on those topological metamaterials, a central scheme of the Würzburg-Dresden Cluster of Excellence ct.qmat - Complexity and Topology in Quantum Matter.

Novel topological phenomena

A related motif of solid state research in Würzburg is the discovery and characterization of novel topological phenomena. This concerns the study of topological insulators, which are insulating in the bulk, but feature conducting surface states.

Scientists worldwide engage in intensive research on these materials as they exhibit compelling physical phenomena. One day, this research may lead to advances in semiconductor technology or in other fields.

The JMU researchers report on their newest results in the journal Nature Physics. Topological insulators are usually considered as isolated (Hermitian) systems. In contrast, scientists can tweak topological metamaterials such as to study the implications of energy exchange with the environment.

These interactions influence the behaviour of the system from the outside, as would be the case for friction. This way, they experimentally verified the non-Hermitian skin effect (NHSE) previously predicted in theory.

All states localize at the edge

The NHSE involves that, in contrast to a common topological insulator, not only a small fraction but all states of the material appear at its edge, i.e. are localized there. This is described by Tobias Helbig and Tobias Hofmann, the joint first authors of the publication. They are both PhD students in the research group of Professor Ronny Thomale, head of the JMU Chair of Theoretical Physics I.

"Our research shows, among other things, that the physical principles known from isolated solid state systems need to be fundamentally modified in the non-Hermitian case," the PhD students explain. The new findings would not yet have a direct application. However, they do have the potential to improve highly sensitive optical detectors, as an example.

Electric circuits as a center of innovation in basic research

The experiments leading to the new results were conducted with the group of Dr. Tobias Kießling and the JMU Chair of Experimental Physics III. Additional contributions and ideas have been brought forward by Professor Alexander Szameit from the University of Rostock. JMU Physicists cooperate with Szameit's team on the topic of topological photonics within the cluster of excellence ct.qmat.

In order to demonstrate the non-Hermitian skin effect experimentally, the JMU team has used electric circuits with periodically arranged elements. Due to their resemblance to the crystal structure of a solid, such artificially arranged experimental settings are classified as a metamaterial.

Applications of topological matter in sight

Prospectively, the research team wants to investigate the interplay between topological states and non-Hermitian physics further. One key question will be to which extent the topological protection of states remains intact when interactions with the environment are present.

In the long term, the team intends to progress towards quantum hybrid circuits in which they plan to embed superconducting or other quantum mechanical circuit elements. Such circuits offer a versatile platform for the discovery of novel phenomena.

„We aim to transfer the insights from topological circuits to other metamaterial platforms in the pursuit of potential applications“, Professor Thomale sums up. This includes optical setups such as photonic waveguides. There, topologically protected states in non-Hermitian systems could prove relevant in the enhancement of signal processing and detectors as well as in the construction of a photonic quantum computer. Eventually, the ultimate scheme in the research on topological metamaterials is the reconnection of novel effects to actual solid states.

Sponsors

The work described was financially supported by the German Research Foundation (DFG) in the Collaborative Research Center SFB-1170 Tocotronics and within the Cluster of Excellence ct.qmat (Würzburg-Dresden).

Wissenschaftliche Ansprechpartner:

Prof. Dr. Ronny Thomale, Chair of Theoretical Physics I, University of Würzburg, T +49 931 31-86225, ronny.thomale@physik.uni-wuerzburg.de

Originalpublikation:

Generalized bulk-boundary correspondence in non-Hermitian topolectrical circuits. Tobias Helbig, Tobias Hofmann, Stefan Imhof, Mohamed Abdelghany, Tobias Kiessling, Laurens W. Molenkamp, Ching Hua Lee, Alexander Szameit, Martin Greiter, Ronny Thomale. Nature Physics, 1 June 2020, DOI: 10.1038/s41567-020-0922-9

Robert Emmerich | Julius-Maximilians-Universität Würzburg

Further reports about: Metamaterial Nature Physics skin topological insulator

More articles from Materials Sciences:

nachricht Carbon-loving materials designed to reduce industrial emissions
06.07.2020 | DOE/Oak Ridge National Laboratory

nachricht Thermophones offer new route to radically simplify array design, research shows
03.07.2020 | University of Exeter

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

Im Focus: ILA Goes Digital – Automation & Production Technology for Adaptable Aircraft Production

Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...

Im Focus: AI monitoring of laser welding processes - X-ray vision and eavesdropping ensure quality

With an X-ray experiment at the European Synchrotron ESRF in Grenoble (France), Empa researchers were able to demonstrate how well their real-time acoustic monitoring of laser weld seams works. With almost 90 percent reliability, they detected the formation of unwanted pores that impair the quality of weld seams. Thanks to a special evaluation method based on artificial intelligence (AI), the detection process is completed in just 70 milliseconds.

Laser welding is a process suitable for joining metals and thermoplastics. It has become particularly well established in highly automated production, for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

 
Latest News

Coupled hair cells in the inner ear – „Together we are strong!“

06.07.2020 | Health and Medicine

Innovations for sustainability in a post-pandemic future

06.07.2020 | Social Sciences

Carbon-loving materials designed to reduce industrial emissions

06.07.2020 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>