| dc.description.abstract | Spintronics is a subtopic of magnonics in which the spin of the electron is used to store and process information. Magnonics is the magnetic analogue of the recently popularised field of plasmonics, which deals with the study and manipulation of plasmons. One key development in the progression of plasmonics was the understanding and manipulation of surface plasmon polaritons, owing to their ability to enhance and confine light. Although data storage devices based on ferromagnetic materials have been widely available for decades, there has been little progress in achieving devices capable of data processing. Antiferromagnetic materials offer an attractive solution, having faster interactions and fewer stray fields in comparison to ferromagnetic devices. As antiferromagnetic materials support surface modes analogues to surface plasmon polaritons, it is suggested that studying these ’surface magnon polaritons’ could further magnonics and by extension spintronics, in a similar manner exploring surface plasmon polaritons furthered plasmonics.
This doctoral thesis aims to comprehensively investigate both surface plasmon and magnon polariton systems with the final intention of furthering spintronic systems at Terahertz frequencies. The lack of surface magnon systems meant it was necessary to study both theoretical surface magnon polaritons and experimental surface plasmon polaritons systems as part of this work. The primary experimental tool used in this work to probe the surface polariton supporting systems was that of spectroscopic ellipsometry.
The thesis comprises four papers, each branching out from the core subject matter. The first and third papers explore the utilisation of spectroscopic ellipsometry to investigate the surface plasmon polaritons supported by patch antennas and wide band gap semiconductors, respectively. These investigations provided crucial insights into the behaviour of surface plasmon polaritons, paving the way for a deeper understanding of spintronic systems.
The second paper takes on a theoretical perspective, employing simulations to investigate surface magnon polaritons in the antiferromagnetic semiconductor MnF2. This work was the closest in subject matter to the thesis topic investigating prism coupling into possible spintronic devices.
The fourth paper focused on the growth of antiferromagnetic semiconductor CuFeS2 and its ellipsometric characterisation in the IR, visible, and UV ranges. This comprehensive characterisation is of paramount importance, as it enables us to comprehend the growth and properties such as band gap, carrier concentration and phonons that could affect the theorised surface magnon polaritons supported by the material. | en_US |
