Chern Insulator · Chiral Edge State · Hall Conductance = e²/h · No External B
Parameters
1
σxy [e²/h] — Hall conductance
H = v(k×σ)·ẑ + m(k)σz
m(k) = M - Bk² (mass inversion)
Chern # C = sgn(M)·Θ(|M|>B|k²|)
QAHE: C=1 → σxy=e²/h (no B field!)
When magnetization M exceeds a critical value, the band topology changes — the Chern number becomes nonzero and a single chiral edge mode appears, giving σ_xy = Ce²/h without Landau levels.