Terahertz Electron Paramagnetic Resonance Ellipsometry

EQUATE/NCMN seminar held on August 21, 2024, featuring Viktor Rindert of Lund University, Lund, Sweden. Abstract: Electron paramagnetic resonance (EPR) has evolved significantly since its first observations in the 1940s in the Soviet Union, becoming a well-established field. However, there remains much to explore, particularly in high-frequency EPR. THz EPR ellipsometry has emerged as a promising front-runner in this domain, offering access to a great frequency range with unparalleled spectral resolution. So far, THz EPR ellipsometry has been performed on point defects in GaN and Ga2O3, yielding a new understanding of these defect's properties within wide-bandgaps semiconductors. In this seminar, we will explore the impact of conducting EPR in the frequency domain, discuss the models we employ for the frequency-dependent magnetic permeability tensor, and consider potential future directions for advancing this innovative technique.