Discovery of topological LC circuits transporting EM waves without backscattering

December 28, 2018, National Institute for Materials Science
Microstrip arrays used in this research. Credit: NIMS

NIMS has succeeded in fabricating topological LC circuits arranged in a honeycomb pattern where electromagnetic (EM) waves can propagate without backscattering, even when pathways turn sharply. These circuits may be suitable for use as high-frequency electromagnetic waveguides, which would allow miniaturization and high integration in electronic devices such as mobile phones.

Researchers are seeking topological properties with functions that are not affected even if the sample shapes are changed. Topological properties were first discovered in electron systems, and more recently, the notion has been developed for light and microwaves for building optical and electromagnetic waveguides immune to backscattering. However, realization of topological properties in light and microwaves normally requires gyromagnetic materials under an , or some other . In order to match existing electronics and photonics technologies, it is important to achieve topological properties based on conventional materials and simple structures.

In 2015, this demonstrated topological properties in light and microwaves in a honeycomb lattice of dielectric cylinders such as silicon. This time, the team reported that in a microstrip, attain topological properties when the metallic strips form a and the intra-hexagon and inter-hexagon strip widths are different. The team also fabricated microstrips and measured electric fields on their surfaces, and successfully observed the detailed structure of topological electromagnetic modes, where vortices of electromagnetic energy polarized in a specific direction are generated during the .

This research demonstrates that topological propagation of electromagnetic waves can be induced using conventional materials in a simple structure. Because topological electromagnetic wave propagation is immune to backscatter even when pathways turn sharply, designs of compact electromagnetic circuits become possible, leading to miniaturization and high integration of electronics devices. In addition, the direction of vortex and the vorticity associated with topological electromagnetic modes may be used as data carriers in high-density information communications. All these features may contribute to the development of advanced information society represented by IoT and autonomous vehicles.

Explore further: Topological photonic crystal made of silicon

More information: Yuan Li et al, Topological LC-circuits based on microstrips and observation of electromagnetic modes with orbital angular momentum, Nature Communications (2018). DOI: 10.1038/s41467-018-07084-2

Related Stories

Topological photonic crystal made of silicon

January 19, 2017

WPI-MANA researchers derive topological photonic states purely based on silicon, which can lead to the development of new functions and devices through integration with semiconductor electronics

A novel topological insulator

October 12, 2018

For the first time, physicists have built a unique topological insulator in which optical and electronic excitations hybridize and flow together. They report their discovery in Nature.

Bismuth shows novel conducting properties

September 12, 2018

A team of international scientists including Maia G. Vergniory, Ikerbasque researcher at DIPC and UPV/EHU associate, has discovered a new class of materials, higher-order topological insulators. Theoretical physicists first ...

Recommended for you

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

Physicists reveal why matter dominates universe

March 21, 2019

Physicists in the College of Arts and Sciences at Syracuse University have confirmed that matter and antimatter decay differently for elementary particles containing charmed quarks.

ATLAS experiment observes light scattering off light

March 20, 2019

Light-by-light scattering is a very rare phenomenon in which two photons interact, producing another pair of photons. This process was among the earliest predictions of quantum electrodynamics (QED), the quantum theory of ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.