Abstract
Artificial spin ices (ASIs) consisting of arrays of magnetic bars are key systems in the study of geometric frustration in magnetic systems. Of particular interest are quasicrystal (QC) ASIs, in which the lack of translational symmetry and the varying coordination number of interacting bars allow for topologically enhanced frustrated magnetization to occur. We have directly observed the formation of magnetic vortexes within the vertices of a QC-ASI as a metastable transient state, during the magnetization reversal process. We observed that the vortexes primarily form in a specific subset of the vertex motif types. Micromagnetic simulations show that although these magnetic vortexes result in an increase in the local energy of the vertex before the magnetization of the bars reverses to align with the applied magnetic field, the overall energy increase is lower than the higher energy motif configurations that would result from reversal of the magnetization in the connecting bar.
Original language | English (US) |
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Article number | 094424 |
Journal | Physical Review B |
Volume | 98 |
Issue number | 9 |
DOIs | |
State | Published - Sep 25 2018 |
Funding
This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Science and Engineering Division. Use of the Center for Nanoscale Materials was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. We acknowledge J. Pearson for help with thin film deposition. A.A. thanks the National Science Foundation for support for a summer intern position at Argonne under Grant No. DUE-1564720 “Promoting STEM Student Success through Individualized Coaching and Interdisciplinary Community”.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics