# magnum.fd, a fork of MicroMagnum

We present the fork magnum.fd of the finite-difference code MicroMagnum that performs micromagnetic computations on CPU as well as GPU. The original project was developed at the University of Hamburg by the MicroMagnum team. Finite-difference codes are well suited for cuboid structures and magnetic thin films.

This fork is aimed to extend the functionality of MicroMagnum. In the long term we want to change the interface to be compatible to that of magnum.fe. As first extensions we introduce a direct minimization algorithm and a GmshShape class that is able to handle a large number of CAD and mesh file formats for the import of geometries.

The new minimizer can be called on any micromagnetic solver object

solver = create_solver(world, [StrayField, ExchangeField])
solver.minimize()


The GmshShape class is able to read a number of geometry files. Usually you do not only need the shape but also a mesh that fits the geometry of the shape. In order to create the shape and a suitable mesh from a geometry file you can do the following

mesh, shape = GmshShape.with_mesh_from_file("sample.brep", (5e-9, 5e-9, 5e-9))


Here the second argument defines the cell size of the mesh.

# magnum.fe, a micromagnetic finite-element code

We present magnum.fe. A finite element code based on FEnICS. magnum.fe implements state-of-the art algorithms for the solution of dynamical problems. Due to the use of the high level finite-element package FEniCS, magnum.fe can be easily extended to your needs.

Finite-element codes are well suited for the simulation of complex three-dimensional structures. By now magnum.fe is able to solve the Landau-Lifshitz-Gilbert equation with the most important effective field contributions, i.e. exchange field, demagnetization field, external field and uniaxial anisotropy field. The demagnetization-field problem is either solved by a shell-transformation method or a hybrid FEM/BEM method. Furthermore magnum.fe solves a spin-diffusion model for the simulation of spin torque effects in both multilayer structures and domain walls.

We are planning a number of extensions and improvements in the near future. Follow this blog to stay up to date.

# micromagnetics.org launched

Welcome to micromagnetics.org. We are a group of scientists from the Vienna University of Technology that develop micromagnetic simulation software. Here we want to share the progress of software development and additional information of micromagnetics.

For an introduction to the theory of micromagnetism, see Micromagnetism.

For information on our simulation software, see Software.