Theorem: G h / (2 e^2) - T_n = 0 (single-channel Landauer conductance identity)

Theorem (Landauer-channel canonical): G = 2 e^2 T_n / h rearranges to G h / (2 e^2) = T_n, i.e. dimensionless G / G_0 equals transmission T_n of the open channel. Canonical sympy pins: e_ch, h, T_n = sp.symbols('e h T_n', positive=True); G…