TMOs (Transition Metal Oxides) are of great interest in science and industry thanks to their unique properties including ferroelectricity (which can change their electrical polarisation when an external voltage is applied, something that can be employed in numerous electronic devices such as memory and electro-mechanical actuators), and superconductivity (which allows an electric current to be conducted without energy dissipation, something of great interest in electric motors and magnetic sensors). Traditionally, attempts to manipulate these properties have been carried out by altering the chemical composition or acting on the structure of the compound. The TeraFox (Terahertz Cavity Engineering of Functional Oxides) project, co-led by Ekaterina Khestanova, a a postdoctoral researcher at ICFO, and David Pesquera, a postdoctoral researcher at ICN2, proposes a completely new approach, using light.
“Instead of applying mechanical stress or an electric field, we want to act on the properties of the TMOs by placing them inside a terahertz cavity, where we ‘trap’ the light between two mirrors. This is not visible light, but rather electromagnetic waves of a precise length, with the exact energy to allow us to interact with these materials”, explains Ekaterina Khestanova.
The challenge of this project lies as much in the design and production of the cavity as in its coupling with the TMOs. To succeed would mean having a new, more efficient method to control the functionality and optimise the properties of materials with a wide range of applications, from energy saving and storage to the development of much more precise sensors or the manufacturing of more efficient medical devices and computers.