WEYL SEMIMETAL

Weyl points in k-space, topological Fermi arcs, Berry curvature monopoles
Weyl Semimetal

H(k) = v_F k·σ near Weyl node

Topological charge (Chern number):
C = ±1 (monopole of Berry curvature)

Nielsen-Ninomiya: Weyl points come in ±1 pairs

Fermi arcs: surface states connecting projections of bulk Weyl points

Chiral anomaly: B·E pumps charge between nodes → negative magnetoresistance