Physicists advance understanding of electrical vortices in certain materials

May 26, 2015 by Chris Branam, University of Arkansas

Computational physicists have developed a novel method that accurately reveals how electrical vortices affect electronic properties of materials that are used in a wide range of applications, including cell phones and military sonar.

Zhigang Gui, a doctoral student in physics at the University of Arkansas, and Laurent Bellaiche, Distinguished Professor of physics at the U of A, along with Lin-Wang Wang at Lawrence Berkeley National Laboratory, published their findings in Nano Letters, a journal of the American Chemical Society.

Gui used supercomputers at Oak Ridge National Laboratory to perform large-scale computations to determine the of electrical vortices in , which generate an electric field when their shape is changed.

An electrical vortex occurs when the electric dipoles arrange themselves in an unusual swirling movement, Bellaiche said. In this ferroelectric system, electrical vortices are created and determined by the temperature of the material, Bellaiche said.

The simulations also revealed that the existence of an electrical vortex increases the band gap – the major factor determining a material's conductivity – in this material, which offers insight to the controversial issue about the origin of the conductivity of electrical vortices.

"By changing temperature we are changing the band alignment," Gui said. "Imagine having the same system having two different band alignments, which can lead to different applications. When decreasing temperature, our systems can transform from a Type-I band alignment, which favors light-emitting devices, to a Type-II band alignment, which favors sensors in semiconductor industries."

Explore further: Physicists predict Fano resonance in lead-free relaxors

More information: "Electronic Properties of Electrical Vortices in Ferroelectric Nanocomposites from Large-Scale Ab Initio Computations." Nano Lett., 2015, 15 (5), pp 3224–3229 DOI: 10.1021/acs.nanolett.5b00307

Related Stories

Porous, layered material can serve as a graphene analog

May 19, 2015

An electrically conductive material, with layers resembling graphene (single sheet of graphite), was synthesized under mild conditions using a well-known molecule that allows good electronic coupling of nickel ions and organic ...

Recommended for you

Engineering cellular function without living cells

March 25, 2019

Genes in living cells are activated – or not – by proteins called transcription factors. The mechanisms by which these proteins activate certain genes and deactivate others play a fundamental role in many biological processes. ...

What ionized the universe?

March 25, 2019

The sparsely distributed hot gas that exists in the space between galaxies, the intergalactic medium, is ionized. The question is, how? Astronomers know that once the early universe expanded and cooled enough, hydrogen (its ...

Catalyst advance removes pollutants at low temperatures

March 25, 2019

Researchers at Washington State University, University of New Mexico, Eindhoven University of Technology, and Pacific Northwest National Laboratory have developed a catalyst that can both withstand high temperatures and convert ...

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.