(a) Lateral view schematic of a typical nanofabricated superconductor–insulator–superconductor junction. Bottom and top film have order parameter amplitudes Δ_B and Δ_T. We depict a distribution of transmission channels T₁, …, T_N, most (green) of low and few (red) of high transparency. (b) Energy levels for a purely cos(φ) potential (grey) vs realistic potential including higher-harmonics (red). There is a discrepancy between the energy levels in the two models, which generally increases at higher levels. Adapted from [6].