Unveiling hidden states of matter: Investigating strongly coupled materials using terahertz spectroscopy

Understanding the physics of strongly coupled materials is important for a variety of scientific problems. At low temperatures, strongly coupled matter appears as quantum materials, where the influence of quantum mechanics on macroscopic properties is undeniable. At high temperatures and pressures, one finds warm dense matter, an exotic phase that is not well described by condensed matter or plasma physics theories. Understanding these fascinating states, some of which can only be created transiently or irreversibly, requires that materials properties be determined incisively. Furthermore, probing multiple observables is essential to determine how the relevant degrees of freedom interact. In this talk, I will present the use of single-shot terahertz spectroscopy to probe strongly coupled matter. Terahertz spectroscopy has been used in many scientific areas because of its sensitivity to fundamental degrees of freedom that uniquely characterize a system. This makes it an ideal tool for investigating strongly coupled matter. I will first discuss the appeal and utility of the single-shot terahertz technique as a method for studying irreversible phase transformations. I will then show demonstrative examples where I used this technique to gain vital insight into complex systems and transformations that could not be obtained by normal stroboscopic methods.