Dependence of energy barrier reduction on collective excitations in square artificial spin ice: A comprehensive comparison of simulation techniques

Sabri Koraltan, Matteo Pancaldi, Naemi Leo, Claas Abert, Christoph Vogler, Kevin Hofhuis, Florian Slanovc, Florian Bruckner, Paul Heistracher, Matteo Menniti, Paolo Vavassori, Dieter Suess

We perform micromagnetic simulations to study the switching barriers in square artificial spin ice systems consisting of elongated single domain magnetic islands arranged on a square lattice. By considering a double vertex composed of one central island and six nearest neighbor islands, we calculate the energy barriers between two types of double vertices by applying the simplified and improved string method. We investigate by means of micromagnetic simulations the consequences of the neighboring islands, the inhomogeneities in the magnetization of the islands and the reversal mechanisms on the energy barrier by comparing three different approaches with increasing complexity. The micromagnetic models, where the string method is applied, are compared to a method commonly in use, the mean barrier approximation. Our investigations indicate that a proper micromagnetic modeling of the switching process leads to significantly lower energy barriers, by up to 35% compared to the mean-barrier approximation, so decreasing the expected average life time up to seven orders of magnitude. Hereby, we investigate the influence of parallel switching channels and the conceptional approach of using a mean-barrier to calculate the corresponding rates.

Physics of Functional Materials
External organisation(s)
Stockholm University, CIC nanoGUNE BRTA, Eidgenössische Technische Hochschule Zürich, Paul Scherrer Institute, Ikerbasque Basque Foundation for Science
Physical Review B
No. of pages
Publication date
Peer reviewed
Austrian Fields of Science 2012
103018 Materials physics, 101014 Numerical mathematics
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