High-frequency response and reversal dynamics of two-dimensional magnetic dot arrays

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Abstract
Results from simulations of dynamic response for finite arrays of single domain magnetic dots are presented. Linear and nonlinear high-frequency properties are discussed, and a relevance of these properties to magnetization reversal in switching processes is shown. Particular attention is given to effects of array geometry and applied field orientation. The direction of an applied field relative to the array sides is found to be important for determining degeneracies in the linear magnetostatic mode spectrum. Nonlinear microwave response is also examined by simulating effects of strong rf fields, and routes to chaos are found that depend on the field orientation. A connection between magnetostatic mode excitation and reversal times under a switching field is suggested. A consequence is a dramatic slowing of reversal rates for a range of dot packing densities.