Investigation of the dynamics of twisted bilayer artificial spin ice
| dc.contributor.author | Popy, Rehana Begum | |
| dc.contributor.examiningcommittee | Southern, Byron (Physics and Astronomy) | en_US |
| dc.contributor.examiningcommittee | Lierop, Johan van (Physics and Astronomy) | en_US |
| dc.contributor.supervisor | Stamps, Robert | |
| dc.date.accessioned | 2022-03-09T21:44:24Z | |
| dc.date.available | 2022-03-09T21:44:24Z | |
| dc.date.copyright | 2022-03-09 | |
| dc.date.issued | 2022-03-09 | |
| dc.date.submitted | 2022-03-09T20:34:50Z | en_US |
| dc.degree.discipline | Physics and Astronomy | en_US |
| dc.degree.level | Master of Science (M.Sc.) | en_US |
| dc.description.abstract | Artificial spin ice consists of patterned arrays of interacting ferromagnetic nanomagnets. By exploiting the interactions between the individual elements, we can realize some fascinating behavior of these arrays to create new functionalities. Also, advancements in lithographic processing and film growth have enabled the creation of more complex structures by going beyond two-dimensional designs. This thesis is a numerical study of field-driven dynamics in the bilayer artificial spin ice (BASI) system in which the layers are twisted with respect to each other. The goal is to understand how magnetization dynamics are affected by adjusting the layer separation and layer rotation. We study the square and pinwheel geometries of bilayer artificial spin ice and compare outcomes. The initial segment of this thesis is an analysis of the interaction energy between the layers as a function of layer separations and layer rotations to better understand how the energetics of the bilayer artificial spin ice system are affected by interlayer coupling strength. This work also addresses magnetic field-induced vertex dynamics in square and pinwheel BASI. A numerical study of magnetization reversal processes in BASI systems under the influence of a uniform magnetic field reveals the nature of low energy states that appear during the process. The effect of layer rotation on the vertex dynamics of the system is also investigated under different orientations of the field. The final part of this thesis is dedicated to the study of thermally driven dynamics in BASI to explore the low-temperature steady states available to these systems. The aim is to look for low-temperature ordering that might arise in BASI systems and to investigate how it changes for different layer separations and layer rotations. The results presented here demonstrate that bilayer artificial spin ice can serve as a playground to study the out-of-equilibrium dynamics owing to its increased degrees of freedom. Bilayer artificial spin ice can play an important role in the field of nanomagnetic computation and neural networks, for which it can provide a large number of nonlinear, connected nodes (nanomagnets). | en_US |
| dc.description.note | May 2022 | en_US |
| dc.identifier.uri | http://hdl.handle.net/1993/36361 | |
| dc.language.iso | eng | en_US |
| dc.rights | open access | en_US |
| dc.subject | nanomagnetism | en_US |
| dc.subject | artificial spin ice | en_US |
| dc.subject | frustration | en_US |
| dc.subject | magnetism | en_US |
| dc.title | Investigation of the dynamics of twisted bilayer artificial spin ice | en_US |
| dc.type | master thesis | en_US |