Graphene, a single sheet of carbon atoms, has many extreme electrical and mechanical properties. Two years ago, researchers showed how two sheets laid on top of each other and twisted at just the right angle can become superconducting, so that the material loses its electrical resistivity. New work explains why this superconductivity happens in a surprisingly high temperature.

Researchers at Aalto University and the University of Jyvaskyla showed that graphene can be a superconductor at a much higher temperature than expected, due to a subtle quantum mechanics effect of graphene's electrons. The results were published in Physical Review B. The findings were highlighted in Physics viewpoint by the American Physical Society, and looks set to spark lively discussion in the physics community.

The discovery of the superconducting state in twisted bilayer graphene was selected as the Physics breakthrough of the year 2018 by the Physics World magazine, and it spurred an intense debate among physicist about the origin of superconductivity in graphene.

Although superconductivity was found only at a few degrees above the absolute zero of temperature, uncovering its origin could help understanding high-temperature superconductors and allow us to produce superconductors that operate near room temperature. Such a discovery has been considered one of the "holy grails" of physics, as it would allow operating computers with radically smaller energy consumption than today.

The new work came from a collaboration between Paivi Torma's group at Aalto University and Tero Heikkila's group at the University of Jyvaskyla. Both have studied the types of unusual superconductivity most likely found in graphene for several years.

"The geometric effect of the wave functions on superconductivity was discovered and studied in my group in several model systems. In this project it was exciting to see how these studies link to real materials", says the main author of the work, Aleksi Julku from Aalto University. "Besides showing the relevance of the geometric effect of the wave functions, our theory also predicts a number of observations that the experimentalists can check", explains Teemu Peltonen from the University of Jyvaskyla.

Research paper

Related Links
Aalto University
Powering The World in the 21st Century at Energy-Daily.com

Tweet

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

Generating electricity 'out of thin air'
Amherst MA (SPX) Feb 24, 2020
Scientists at the University of Massachusetts Amherst have developed a device that uses a natural protein to create electricity from moisture in the air, a new technology they say could have significant implications for the future of renewable energy, climate change and in the future of medicine. As reported in Nature, the laboratories of electrical engineer Jun Yao and microbiologist Derek Lovley at UMass Amherst have created a device they call an "Air-gen." or air-powered generator, with electri ... read more