Application of Micromagnetics to Magnetic Recording IV : Recording Field and Magnetization Analysis of Recording Write Heads (2)

Analysis of the recording field and magnetization of recording write heads is surveyed as part of a series of articles entitled Applications of Micromagnetics to Magnetic Recording. The present article discusses the speed-up of Landau-Lifshitz-Gilbert (LLG) micromagnetic calculations. In particular, parallelization of the analysis code, introduction of three-dimensional fast-Fourier-transform (FFT), FFT reduction procedures, and storage of the data in binary form are described. Reducing the calculation memory in FFT is important as well as computing speed. The necessity of introducing the FFT is also discussed with regard to the calculation speed for practical applications. Finally, methods to generate the finite-difference cells and to derive the coil field are described.