Calculation of focusing spin wave transducers using the method of micromagnetic simulation

Background and Objectives: Researches in the field of electronic circuit development for microwave informational systems based on magnetization oscillations and waves have been performing since the 1960s of the last century. The surge of interest in spin waves (SW) during the last decade is caused by the perspective to use SW as information carriers on the sub-micromagnetic and nanometer scale that leads to the fabrication of devices on magnonic principles and a significant miniaturization of spin-wave devices. Besides, the effect of spin wave generation by the spin-polarized current in ferromagnetic nanostructures gives opportunities for possible integration of magnonic and spintronic devices. It should be supplemented that apart from the traditional application of spin waves for microwave signal processing, the possibility to fabricate the logic and holographic memory based on effects of propagation and interference of spin waves has been widely discussed recently. The aim of this work is to to develop a new approach for calculating microwave transducers focusing spin waves in thin-film waveguides with a significantly non-uniform distribution of parameters based on the method of micromagnetic modeling. Materials and Methods: Mic romagnetic simulations were performed by using the free software “Object Oriented Micromagnetic Framework” (OOMMF) provided by the National Institute of Standards and Technology. Results: We have shown the possibility to calculate the form of transducers focusing spin waves both in the films with a uniform distribution of magnetic parameters and in the films having the significantly non-uniform equilibrium state. In the last case, the numerical approach remains the only possible. Conclusion: In our work, we have proposed a new method to obtain the form of transducers focusing spin waves in magnetic microstructures. It is based on the approach of micromagnetic simulation of spin wave propagation after their excitation by the point emitter.