Date Time
When Functional Materials Become Squishy
Most people associate terahertz radiation from airport scanners. These radiations can, however, unleash a bag full of surprises when used to interrogate novel materials. An international team of researchers from the Department of Materials in ETH Zurich and Max-Born-Institute in Berlin joined hands to unravel a very fundamental question on the origin of nonlinearities of a characteristic vibrational mode that becomes soft and squishy when approaching towards the phase transition.
In functional materials, we want to have novel effects as large and new as possible with perturbations as small as possible. Though seemingly contradictory, such a requirement can be met by taking the material close to a phase transition, where the material becomes unstable and nonlinear in some form. In ferroelectric materials, for example, a certain vibrational mode becomes “soft” near the phase transition; that is, the frequency of the mode decreas