Skyrmion phases
Compute skyrmion phases using stochastic LLG
MicroMagnetic.jl
A Julia package for classical spin dynamics and micromagnetic simulations with GPU support.
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Features
- Supports classical spin dynamics and micromagnetic simulations.
- Compatible with CPU and multiple GPU platforms, including NVIDIA, AMD, Intel, and Apple GPUs.
- Supports both double and single precision.
- Supports Monte Carlo simulations for atomistic models.
- Implements the Nudged-Elastic-Band method for energy barrier computations.
- Supports Spin-transfer torques, including Zhang-Li and Slonczewski models.
- Incorporates various energy terms and thermal fluctuations.
- Supports constructive solid geometry.
- Supports periodic boundary conditions.
- Easily extensible to add new features.
Quick start
Assuming we have a cylindrical FeG sample with a diameter of 100 nm and a height of 40 nm, we want to know its magnetization distribution and the stray field around it. We can use the following script:julia
using MicroMagnetic
@using_gpu() # Import available GPU packages such as CUDA, AMDGPU, oneAPI, or Metal
# Define simulation parameters
args = (
task = "Relax", # Specify the type of simulation task (e.g., relaxation)
mesh = FDMesh(nx=80, ny=80, nz=30, dx=2e-9, dy=2e-9, dz=2e-9), # Define the mesh grid for the simulation with 80x80x30 cells and 2 nm cell size
shape = Cylinder(radius=50e-9, height=40e-9), # Define the shape of the magnetic structure as a cylinder with 50 nm radius and 40 nm height
Ms = 3.87e5, # Set the saturation magnetization (A/m)
A = 8.78e-12, # Set the exchange stiffness constant (J/m)
D = 1.58e-3, # Set the Dzyaloshinskii-Moriya interaction constant (J/m^2)
demag = true, # Enable demagnetization effects in the simulation
m0 = (1,1,1), # Set the initial magnetization direction
stopping_dmdt = 0.1 # Set the stopping criterion for the simulation based on the rate of change of magnetization dynamics
);
# Run the simulation with the specified parameters
sim = sim_with(args);
# Save the magnetization and the stray field into vtk.
save_vtk(sim, "m_demag", fields=["demag"])The magnetization and the stray field around the cylindrical sample are stored in m_demag.vts, which can be opened using Paraview.