Terahertz Electrodynamics in Transition Metal Oxides

Transition metal oxides (TMOs) are among the most contemporary topics in condensed matter research. For over the past three decades, the most astounding discoveries of high temperature superconductivity, colossal magnetoresistance, multiferroics, topological matter, and several other novel electronic and magnetic phases have been realized and hosted in the TMOs. Almost simultaneously and specifically during the past 5 years, the implementation of terahertz (THz) spectroscopy to unveil the complexity of such materials has delivered unprecedented success. THz spectroscopy extracts material parameters such as dynamic conductivity, dielectric constant, and magnetic permeability in spectral range of 1-20 meV. This imparts the capability to probe a variety of quasiparticles emerging from the electrodynamics of collective, bound and free charge carriers, and complex spin orders, which is the key to decode the complex phases of TMOs class of quantum matter. Herein, the THz spectroscopic investigations of quasiparticle electrodynamics of correlated TMOs are reviewed. Several long-standing issues are resolved and there is enormous potential for a lot more to offer, emphasizing the growing indispensability of THz technology in condensed matter.