mumax3

mumax³ is a GPU-accelerated micromagnetic simulation program developed and maintained at the DyNaMat group at Ghent University.

A speed-up of the order of 100x compared to CPU-based simulations can easily be reached, even with relatively inexpensive gaming GPUs. Additionally, the software is optimized for low memory use and can handle about 16 million FD cells with 2GB of GPU RAM.

Citations and licence

If you use mumax³ in any work or publication, we kindly ask you to cite the references suggested for your specific simulation in the terminal window and in the "references.bib" file found in the outputfolder.

mumax³ is open-source software. You are free to modify and distribute the source code under the GPLv3 licence.

Features

Landau-Lifshitz micromagnetic formalism
Magnetostatic field
Heisenberg exchange
Arbitrary inter-region exchange like RKKY coupling
Dzyaloshinskii-Moriya interaction
Spin-transfer torque (Zhang-Li and Slonczewski)
Uniaxial and cubic magnetocrystalline anisotropy
Thermal fluctuations (Brown)
Voronoi tessellation
Time- and space-dependent material parameters
Arbitrary complex excitation (field, current)
Simulation window can automatically follow a moving domain wall
Edge charges can be removed to simulate an infinitely long geometry
Optional 1D, 2D or 3D periodic boundary conditions

Web GUI

mumax³ includes a browser-based user interface that lets you follow a running simulation or modify it on-the-fly, be it on your local machine or remotely.

Simple scripting

mumax³ provides simple yet powerful input scripting.
E.g., the following example applies a time-dependent external field to a uniform magnet (FMR experiment).

SetGridSize(128, 32, 4)
SetCellSize(5e-9, 5e-9, 5e-9)
Msat  = 860e3
Aex   = 13e-12
alpha = 0.2
m = Uniform(1, 1, 0)

f := 1e9  // 1GHz
A := 0.01 // 10mT
B_ext = Vector(0.1, A*sin(2*pi*f*t), 0)

run(10e-9)

GPU/driver requirements

mumax³ is cross-platform and runs on Linux, Windows and Mac platforms. You need an NVIDIA GPU with compute capability 5.0 or higher, as listed here. You also need to use NVIDIA's proprietary graphics driver, which may already be installed on your system. The benchmark below may guide your GPU choice.

mumax³ GPU perfomance for 2D simulations containing 4 million cells.