Weyl metamaterials offer a novel route to 3D electronic devices

Researchers show how the principles of general relativity open the door to novel electronic applications including the 3D electron lens and electronic invisibility devices.
a) By local manipulation of material parameters, it is possible to tune the properties of charge carriers in Weyl semimetals, b) With suitable local manipulation of material parameters one can tailor the carrier motion and design novel electronic devices such as the electron lens, which focuses the incoming carriers. Picture: Teemu Ojanen.

In the new study Aalto University researchers Alex Westström and Teemu Ojanen propose a method to go beyond special relativity and simulate Einstein’s theory of general relativity in inhomogeneous Weyl semimetals. The theory of Weyl metamaterials combines ideas from solid-state physics, particle physics and cosmology and point a way to fabricate metallic designer materials where charge carriers move like particles in a curved space-time.

The researchers propose Weyl metamaterials, a generalization of Weyl semimetals, that enable new types of electronic devices through geometry engineering.

“The systems we introduced offer a route to make the charge carriers move as if they were living in a curved geometry, providing a tabletop laboratory for simulating curved-space quantum physics and certain cosmological phenomena,” explains Alex Westström.

Weyl semimetals are one example of recently discovered quantum materials that have received a lot of attention. Charge carriers in these materials behave as if they were massless particles moving at the speed of light.

“We discovered that Weyl metamaterials may serve as a platform for exotic electronic devices such as the 3d electron lens, where the trajectories of charge carriers are focused much like beams of light in an optical lens,” says Aalto University Docent Teemu Ojanen.

The electric conduction in Weyl semimetals reflects the physics of Einstein’s special theory of relativity. Nevertheless, special relativity also assumes an absence of gravity, which Einstein formulated as a geometry of space-time.

The theory of Weyl metamaterials also pave the way for fundamentally new electronics applications, for instance the development of electronic invisibility devices. The key idea behind the potential applications is an artificially created curved geometry, which bends the motion of charge carriers in a controlled way.

“In optics it has been known for centuries that light always chooses a trajectory which is the quickest. In a curved geometry, the quickest path does not look like a straight line for those watching outside. The functionality of optical invisibility devices where the beams of light bypass a hidden object is in fact based on application of curved-space geometry. It would be a breakthrough in fundamental research to achieve similar functionality in electronic systems”, adds Ojanen.

The research results were published in Physical Review X on October 29, 2017. The study was performed at Aalto University’s Department of Applied Physics, in the group Theory of Quantum Matter.  The Academy of Finland funded the research.

Further information:

Teemu Ojanen
Aalto University
[email protected]

Article: Designer curved-space geometry for relativistic fermions in Weyl metamaterials Physical Review X 7 2017

Physics Central

  • Published:
  • Updated:
URL copied!

Related news

space key touch guard
Press releases Published:

Sculptor creates freely available design for antimicrobial touch guard to save your hands from germs

The Space Key can be used to touch toilet lids, turn-locks and door handles, slipping after use into a protective cover that kills possible pathogens
Jaana Vapaavuori (left) and Konstantinos Daskalakis (right)
Press releases Published:

EU grants for smart materials and next generation LEDs

Three million euros grants to Assistant Professor Jaana Vapaavuori and Postdoctoral Researcher Konstantinos Daskalakis to make environmentally friendly materials
Rehtori Ilkka Niemelä pitää lukuvuoden avajaispuhetta verkon välityksellä.
Press releases, University Published:

President Ilkka Niemelä: ‘The battered economy does not need a return to the old; it needs a transformation, built anew on the foundation of sustainable development’

Minister of Science and Culture Annika Saarikko and Chair of the Aalto University Student Union Olli Kesseli also spoke at the academic year opening. The opening ceremony was held online.
Townhouses in Malminkartano. Photo: Eija Hasu
Press releases Published:

New survey: 75% of single-family house owners would pay more for an environmentally friendly home

Up to 75% of Finnish single-family house residents would be willing to pay more for a home that promotes sustainable development.