Author of thesis: Bc. Jan Klíma
Acad. year: 2022/2023
Supervisor: Ing. Ondřej Wojewoda, Ph.D.
Reviewer: Dr. Ing. Michal Staňo
Abstract:Magnonics is a branch of physics dealing with spin waves, or their quanta – magnons. Spin waves are one of the candidates for beyond CMOS technology. Circuits and components utilizing the properties of spin waves have the potential to complement or replace the current technologies based on CMOS chips, which are nearing their physical limit. Information processing via spin waves requires the ability to effectively steer spin waves in magnonic circuits, especially in variously bent waveguides connecting individual circuit elements. Due to spin waves’ anisotropic behaviour, this remains on of the challenges to tackle. In the presented thesis, we used corrugating of the magnetic layer of the waveguides, which induces uniaxial magnetic anisotropy, with which we can control the magnetisation landscape in the waveguide with sub-micrometre precision. Using this approach, we can achieve zero-field-propagation of spin waves in desired modes in arbitrary directions. To aid our designs, we developed a model that analyses energy contributions and calculates the resulting effective magnetic field. Using this model and a thorough analysis of the dispersion relation, we designed a bent magnonic waveguide capable of steering spin waves, which we demonstrated by Brillouin light scattering microscopy.
magnonics, spin waves, local magnetisation control, steering spin waves, corrugation, Brillouin light scattering, caustics, curvilinear magnetism, 3D nanostructures
Date of defence
22.06.2023
Result of the defence
Defended (thesis was successfully defended)
Grading
A
Process of defence
Po otázkách oponenta bylo dále diskutováno: Určení grupové rychlosti vlny. Volba směru čar v zatáčce vlnovodu. Dochází k odrazu na rozhraních? Student na otázky odpověděl.
Language of thesis
Czech
Faculty
Department
Study programme
Physical Engineering and Nanotechnology (B-FIN-P)
Composition of Committee
prof. RNDr. Tomáš Šikola, CSc. (předseda)
prof. RNDr. Jiří Spousta, Ph.D. (místopředseda)
prof. RNDr. Bohumila Lencová, CSc. (člen)
prof. RNDr. Radim Chmelík, Ph.D. (člen)
prof. RNDr. Petr Dub, CSc. (člen)
doc. Ing. Stanislav Průša, Ph.D. (člen)
prof. Ing. Miroslav Kolíbal, Ph.D. (člen)
doc. Mgr. Vlastimil Křápek, Ph.D. (člen)
prof. Ing. Jan Čechal, Ph.D. (člen)
doc. Ing. Miroslav Bartošík, Ph.D. (člen)
doc. Ing. Radek Kalousek, Ph.D. (člen)
RNDr. Antonín Fejfar, CSc. (člen)
Supervisor’s report
Ing. Ondřej Wojewoda, Ph.D.
Grade proposed by supervisor: A
Reviewer’s report
Dr. Ing. Michal Staňo
Grade proposed by reviewer: A