Weyl nodes with chirality ±1 as monopoles of Berry curvature; Fermi arc surface states connect their projections
k₀ = 0.80 | Type I Weyl | Fermi arc length = —
A Weyl semimetal hosts pairs of non-degenerate band-touching points (Weyl nodes) carrying
topological charge (chirality) ±1 — monopoles and anti-monopoles of Berry curvature in k-space.
The bulk-boundary correspondence guarantees Fermi arc surface states connecting the k-space
projections of opposite-chirality nodes. Tilting the cone past |t|=1 gives a Type-II Weyl fermion (Lorentz violation).
Berry curvature (hedgehog pattern) diverges at each node.