Nav: Home

New quantum materials offer novel route to 3-D electronic devices

November 07, 2017

Researchers have shown how the principles of general relativity open the door to novel electronic applications such as a three-dimensional electron lens and electronic invisibility devices. In a new study funded by the Academy of Finland, 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 points a way to fabricate metallic designer materials where charge carriers move like particles in curved space-time.

The researchers propose Weyl metamaterials, a generalisation 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," Alex Westström explains.

Weyl semimetals are an 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," Teemu Ojanen says.

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 paves 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's been known for centuries that light always chooses the quickest trajectory. In curved geometry, the quickest path doesn't look like a straight line for those watching from outside. The functionality of optical invisibility devices, where the beams of light bypass a hidden object, is in fact based on the application of curved-space geometry. It would be a breakthrough in fundamental research to achieve a similar functionality in electronic systems," Ojanen adds.
-end-
The research results were published in Physical Review X. The study was performed at Aalto University's Department of Applied Physics, in the group Theory of Quantum Matter.

Article:

Alex Westström and Teemu Ojanen: Designer curved-space geometry for relativistic fermions in Weyl metamaterials Physical Review X 7 2017, https://journals.aps.org/prx/pdf/10.1103/PhysRevX.7.041026, DOI: 10.1103/PhysRevX.7.041026

Inquiries

Academy of Finland Communications
Leena Vähäkylä, Communications Specialist
tel. +358 295 335 068
firstname.lastname(at)aka.fi

Picture: 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.

Academy of Finland

Related Physics Articles:

Twisted physics
A new study in the journal Nature shows that superconductivity in bilayer graphene can be turned on or off with a small voltage change, increasing its usefulness for electronic devices.
Physics vs. asthma
A research team from the MIPT Center for Molecular Mechanisms of Aging and Age-Related Diseases has collaborated with colleagues from the U.S., Canada, France, and Germany to determine the spatial structure of the CysLT1 receptor.
2D topological physics from shaking a 1D wire
Published in Physical Review X, this new study propose a realistic scheme to observe a 'cold-atomic quantum Hall effect.'
Helping physics teachers who don't know physics
A shortage of high school physics teachers has led to teachers with little-to-no training taking over physics classrooms, reports show.
Physics at the edge
In 2005, condensed matter physicists Charles Kane and Eugene Mele considered the fate of graphene at low temperatures.
Using physics to print living tissue
3D printers can be used to make a variety of useful objects by building up a shape, layer by layer.
When the physics say 'don't follow your nose'
Engineers at Duke University are developing a smart robotic system for sniffing out pollution hotspots and sources of toxic leaks.
The coming of age of plasma physics
The story of the generation of physicists involved in the development of a sustainable energy source, controlled fusion, using a method called magnetic confinement.
Physics: Not everything is where it seems to be
Scientists at TU Wien, the University of Innsbruck and the ÖAW have for the first time demonstrated a wave effect that can lead to measurement errors in the optical position estimation of objects.
'Fudge factors' in physics?
What if your theory to model and predict the electronic structure of atoms isn't accounting for dispersion energy?
More Physics News and Physics Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#540 Specialize? Or Generalize?
Ever been called a "jack of all trades, master of none"? The world loves to elevate specialists, people who drill deep into a single topic. Those people are great. But there's a place for generalists too, argues David Epstein. Jacks of all trades are often more successful than specialists. And he's got science to back it up. We talk with Epstein about his latest book, "Range: Why Generalists Triumph in a Specialized World".
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.