WEYL SEMIMETAL

Topological band crossing · Chiral anomaly

k separation 2b 1.0

E field (chiral pump) 0.5

B field (parallel to E) 0.5

Rotation speed 1.0

OBSERVABLES

Chern number (each node)±1

∂_μ j^μ_5 (anomaly)—

LMR (neg. mag. resist.)—

Fermi arc length—

∂_t ρ_χ = χ e²/(4π²ℏ) E·B

Weyl nodes are monopoles of Berry curvature in k-space. Parallel E and B pump chirality (ABJ anomaly): right-handed node fills, left empties. This gives negative longitudinal magnetoresistance — the experimental signature of Weyl semimetals (TaAs, NbP, WTe₂).