IQHE Hall conductance σ_xy = n·(e²/h), n = first Chern number (TKNN 1982)

Integer quantum Hall effect Hall conductance as Chern number (Thouless-Kohmoto-Nightingale-den Nijs 1982). From framework F9 (Chern-Simons + first Chern class), the Hall conductance σ_xy of a gapped 2D band insulator is quantised as σ_xy =…