Geometric Frustration in Nanomagnet Clusters
Open Access
- Author:
- Bartell, Jason M
- Area of Honors:
- Physics
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Peter E Schiffer, Thesis Supervisor
Peter E Schiffer, Thesis Supervisor
Dr. Richard Wallace Robinett, Thesis Honors Advisor - Keywords:
- Geometric Frustration
Nanomagnets
Spin ice - Abstract:
- This thesis presents work relating to the investigation of frustrated magnetism by using clusters of single domain nanomagnet islnds. The work builds off of previous work that studied extended arrays of ferromagnetic nonmagnets designed to provide a 2D, room temperature analogue of artificial spin ice. The advantage to these systems is that, in addition to not needing low temperatures, the individual moments of the patterns can be recorded and used to generate statistics on the moment configurations. The work on nanomagnetic clusters presented here simplifies the artificial spin ice further by examining groupings of four magnets in different geometries. These geometries can all be formed by extracting groups of four adjoining moments from the square lattice. This allows for a comparison of frustrated and unfrustrated interactions that would be found within the extended lattice but permits us to ignore the effects of neighboring magnets. The study of clusters involves several aspects including fabrication, measurement, and image analysis. This thesis gives an overview of the study of nanomagnet clusters, including results and background on geometric frustration, with additional emphasis on image analysis. The results of the study show that the interaction energy of a few moments is more likely to be minimized when the moments are isolated. In addition, frustrated interactions are less likely to be minimized than unfrustrated interactions. There is strong evidence to suggest that frustrated interactions do not readily achieve a round state for some physical reason relating to their frustration.