Scanning gate microscopy of non-retracing electron-hole trajectories in a normal-superconductor junction - code

We theoretically study the Scanning Gate Microscopy (SGM) of the electron and hole trajectories in a Normal-Superconductor (NS) interface where a Quantum Point Contact (QPC) is embedded. In the zero bias case, electrons after getting Andreev reflected as a hole from the NS interface, have a similar wave vector, which causes the self-interference pattern in the SGM conductance plots. For the nonzero bias case, electrons and holes have different wave vectors. As a result, a disturbed and branched flow SGM conductance map is observed. Also by plotting the probability currents, we can clearly see the difference in two cases. The code contains all of these calculations.