The physics department at Northeastern University is trying to get more out of materials. A physics professor Gregory Fiete says they are trying to explore ways that
will give us more out of material. “We could take materials that might be in common use in electronics, like silicon or gallium arsenide in your smartphone, and
we can get them to do things that they don’t do right now.”
Materials like silicon have helped researchers to build low-cost, reliable, energy- efficient circuits to power electronics. Physicists are working on advancing new and more complex material. In recent years, physicists have been able to change how these new materials interact with light or conduct electricity, among other things, by connecting them to a battery or putting them near a strong magnet. This has opened up possibilities for engineering for the next generation electronics.
Fiete and his doctoral student Michael Vogl has a theoretical way to predictably alter these electrical and magnetic properties by shooting the material with a laser.
The characteristics of a material, including whether it is an effective conductor of electricity, depends on the arrangement of the electrons within the material. A steady magnetic current or field from a battery can change that arrangement. A laser too can do this, but it’s a little more complicated to predict. Lasers are basically well-organised waves of light; the electromagnetic fields that they create fluctuate constantly. The pulse of a light moving through material changes the properties of this material, often on a short time scale. The work done by Fiete and his student helps understand what type of pulse is to be used to get a certain effect.
The constantly changing nature of light can also help physicists shift the materials into new states. This can’t be accessed by any other method. It is possible that some of these new states might make the material more sensitive to magnetic or electric fields, which can be used to improve medical technology and security sensors. It can also be made more efficient at carrying information and could be used to speed up internet connections.