pub fn step_transmission(normal_energy_ev: f64, delta_u_ev: f64) -> f64Expand description
Transmission probability through a potential step delta_u_ev for an
electron of normal energy normal_energy_ev = E cos²θ (Verduin Eq. 3.145,
p. 102): zero when E_n + ΔU <= 0 (the electron cannot get over), else
4 s / (1 + s)² with s = sqrt(1 + ΔU / E_n). Symmetric under exchanging
the two sides (s -> 1/s).