RESEARCHERS DEVELOP NEW METHOD FOR DETERMINING MATERIAL RESPONSE TO ELECTRIC FIELDS

FAYETTEVILLE, Ark. - At the atomic scale, small changes create large responses in semiconductor or ferroelectric devices that have applications in telecommunications, lasers, computer chips, medical imaging and military sensors. Researchers still understand little of a material's response to an electric field, but University of Arkansas researchers have developed a new simple, efficient method for predicting a given material's response under an electric field.

Huaxiang Fu, assistant professor of physics, and his colleague, professor Laurent Bellaiche, presented their findings at a recent meeting of the American Physical Society.

Fu and Bellaiche specialize in computational physics, a field that allows researchers to predict properties of novel materials by examining their atomic arrangement. Through knowledge of the chemical species and chemical composition, researchers can predict many things about a material, including the location of the atoms, the formation of chemical bonds, the durability of a material, its insulating or conducting properties and its optical properties.

Researchers have tried to take this prediction a step further--to use computational physics to predict how novel materials respond to an electrical field. This has proved challenging, and until now the only methods to do so have proved complicated and time-consuming.

"We wanted to find a simple but reliable way" for researchers to determine how a material's properties change under the application of an electric field, Fu said.

Fu and Bellaiche applied and successfully tested the new method on two very different materials (semiconductor GaN and ferroelecric oxide PbTiO3) to predict changes in properties including the length of the material, the movement of atoms and a change in the flow of electrons.

The method will allow theorists a simple, efficient method for looking at electric fields applied to a variety of other materials and other properties.