Figure 4: Hard gap and Andreev transport.
From: Ballistic superconductivity in semiconductor nanowires
(a) Above-gap (black) and subgap (blue) conductance for device E. Red curve is a theory prediction based on single channel Andreev reflection, agreeing perfectly with experimental data without any fitting parameter up to the dip on the right side of the plateau where the second channel starts conducting. (b,c) Five typical gap traces corresponding to the five colour bars indicated in d plotted on a linear and logarithmic scale. The subgap conductance is suppressed by a factor up to 50 for the lowest conductance (red trace). (d) Subgap conductance Gs as a function of above-gap conductance Gn for device A. Red curve is the theory prediction assuming only Andreev processes. Inset shows Gs versus Gn taken at different magnetic fields.
