Spin Waves ________________________________________________________ Localized Defect Modes in a Two-Dimensional Array of Magnetic

Received (dates will be inserted by IEEE). Abstract—Microwave properties of an array of magnetic nanodots in a ferromagnetic state having a point defect – a dot with inverted magnetization or different material parameters- are considered. The existence of a single point defect in a dot array may lead to the appearance of several localized modes: one “defect ” eigenmode and several “well ” modes, the number and structure of which strongly depend on the magnetostatic interaction between the dots. It is shown that by performing a ferromagnetic resonance (FMR) experiment in an array of magnetic dots containing a small number of defects it is possible to obtain the information about the entire spin-wave spectrum of the array. Index Terms—Spin waves, magnonic crystal, magnetic dot, ferromagnetic resonance