Parallel micromagnetic simulations using fourier methods on a regular hexagonal lattice

Computer simulations of the microscopic magnetic dy namics of thin films provides a new means for developing theoretical understanding of the behaviour of magnetic recording materials and a possible way of relating material parameters to magnetic behaviour. Such simulations have become possible recently because of the availability of high performance supercomputers (such as the Connection Machine we have been using) and by improvements in algorithms for evaluating magnetic interactions. Elsewhere Mansuripur and Giles have discussed the application of Fourier methods to computation of the long range demagnetizing field for simulations of magnetic films. Here, we discuss the proper implementation of the Fourier technique on a two dimensional hexagonal lattice. A naive transcription of the method as used for a rectangular lattice leads to serious aliasing problems for short wavelengths. The implementation described here reduces these effects.