Executive Summary : | Quantum materials exhibit multiple interactions with comparable energy scales, leading to an array of electronic quantum phases. To implement quantum materials in quantum computation technologies, researchers need definitive answers to the microscopic origins of these phases, their energy scales, and how they are coupled to the crystal lattice. The symmetry of the crystal lattice is crucial in understanding these interactions. The proposal aims to investigate the microscopic origins of electronic quantum phases by measuring dynamics of lattice, spin, and charge degree of freedoms in the THz domain and determine how dynamics, especially spin dynamics in metallic systems, are sensitive to the underlying Fermi surface topology. Raman scattering will be used to access various low-energy collective excitations close to the Fermi surface, including phonons, magnons/fractionalized excitations, and electron-hole pairs. Vibrational Raman scattering will be used to search for soft phonons in single crystals of K₂IrBr₆, which undergo multiple structural transitions from cubic-to-tetragonal-to-monoclinic as they cool down from room temperature. Magnetic Raman scattering will be used to probe one-magnon scattering in thin films of SrRuO₃, and epitaxial strain engineering will be used to investigate the impact of Fermi surface topology on the magnon decay process in SrRuO₃. Lastly, pulsed laser deposition will be used to deposit EuO thin films on KTaO₃ substrates, aiming to determine the electron-electron correlation strength of 2D electron gas at heterointerfaces of EuO/KTaO₃. Successful implementation of these activities will establish Raman scattering as a valuable tool for studying collective orders in exotic thin films. |