Terahertz Electron Paramagnetic Resonance Ellipsometry defect characterization in ultrawideband gap monoclinic gallium oxide and related alloys
Abstract
This proposal aims to explore and exploit free-space propagation plane wave optical measurement techniques (ellipsometry) for detection of electron paramagnetic resonance (EPR) in ultrawideband gap (UWBG) metal oxides, at ultrahigh frequencies and high magnetic fields, and thereby to establish terahertz (THz)-EPR-Ellipsometry (THz-EPR-E). In this new approach, multiple significant and potentially paradigm shifting advantages over existing EPR methods will be exploited which can provide new and significant insight into the fundamental physics of magnetic resonance for UWBG metal oxides and many other solid state materials. A significant enhancement in sensitivity of six to eight orders of magnitude towards the detectability and the characterization of spin densities is estimated by this new approach over traditional (X-band absorbance based) EPR. Therefore, defect related spin properties in UWBG semiconductor thin film heterostructures can be investigated. Further, the implementation of the concept of ellipsometry dispenses with the need of a fixed resonant cavity, and tunable cavities will be augmented further increasing the sensitivity to small spin densities. In addition to the g-tensor, the gyromagnetic frequency dependent permittivity tensor of a single spin can be reconstructed from the Mueller matrix element information measured in the ellipsometry experiment. This information permits to identify the direction of a spin within the lattice. In addition, an ellipsometry instrument will be constructed that can measure the full Mueller matrix, the chirality and hence the type of a defect can be identified. This information will help to reconstruct the directional dependencies of the g-factor of defects, and, in comparison with first principle calculations, will improve our understanding of defects and their crystallographic relationships within complex metal oxides.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 21, 2022
- Source ID
- FA95502110259XX0
Entities
People
- Mathias Schubert
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Nebraska system