FROM ONE PRECESSING MOMENT TO A SKYRMION
Micromagnetics: how magnetization finds its own texture
Nobody tells the magnetization where to point. Exchange, the stray field, anisotropy and damping decide it together. Start with one moment circling a field, build a domain wall and a spin wave from the same energy, then push a skyrmion along a track and check what its charge really says.
One moment and its grid · Chapters 1–3
What moves a magnetization
Watch one moment circle a field and settle, see how a magnet’s shape picks its easy axis, then let exchange smooth the magnetization and decide how fine the grid must be.
Start with one moment →Textures that move · Chapters 4–8
Walls, waves and skyrmions
Push a domain wall past its Walker field, launch a spin wave, close a wall into a skyrmion, drive it with a current, then read a research paper’s charge figures yourself.
Start with a domain wall →Eight chapters, with examples and experiments
01 L1
A magnetic moment circles a field before it settles
Why does a magnet in a field circle around it instead of turning straight to face it?
Read and try →02 L2
A nanomagnet’s shape sets its easy axis and how it switches
Why does a flat rectangle of magnetic film point along its long side, and how hard must you push to reverse it?
Read and try →03 L2
Exchange smooths the magnetization and sets how fine the mesh must be
How small must the cells of a micromagnetic simulation be, and how can you tell they are small enough?
Read and try →04 L3
A field drives a domain wall only so fast
Why does a domain wall speed up with the field only up to a threshold, and how does interfacial DMI move that threshold?
Read and try →05 L3
How a small tilt travels through a magnet as a spin wave
What wavelength does a spin wave of a given frequency have in a perpendicular film, and how far does it travel before damping stops it?
Read and try →06 L3
Why a skyrmion has a set size and a whole-number charge
What sets the size of an isolated skyrmion in a film with interfacial DMI, what does its topological charge count, and why is the computed charge not exactly −1 next to an edge?
Read and try →07 L4
A current pushes a skyrmion at an angle, and edges and weak spots decide where it ends up
Why does a current move a skyrmion at an angle, and what do an edge and a weak spot do to that motion?
Read and try →08 L4
How to read a skyrmion charge and a pinning threshold in a simulation
When a simulation reports a skyrmion charge that is not a whole number, or a current at which a skyrmion breaks free, how do you tell physics from numerical error?
Read and try →