PhD: Ultrafast Terahertz Spectroscopy of Multi-Functional Materials

This thesis targets to study rare-earth iron-based oxide materials (orthoferrites) for future information technologies in the THz domain. We foresee to use intense electromagnetic pulses in the THz range both as external probe and as an external perturbation to study these materials. It has been shown by optical pump-probe studies that antiferromagnetic iron-based perovskite systems possess magnetization dynamics in the THz frequency domain. For instance, one key challenge is the control of a phase transition allowing to manipulate either the magnetization dynamics or the terahertz absorption of the material. Throughout this project thesis one selected orthoferrite material exhibiting several intrinsic magnetic phase transitions will be studied. One key idea is to induce with phase transition dynamically through an optical near-infrared or a terahertz pump pulse and to monitor the resulting dynamics.