Title: Transport signatures of topological superconductivity in a proximity-coupled nanowire,
Abstract: We study the conductance of a junction between the normal and superconducting
segments of a nanowire, both of which are subjected to spin-orbit coupling and
an external magnetic field. We directly compare the transport properties of the
nanowire assuming two different models for the superconducting segment: one
where we put superconductivity by hand into the wire, and one where
superconductivity is induced through a tunneling junction with a bulk s-wave
superconductor. While these two models are equivalent at low energies and at
weak coupling between the nanowire and the superconductor, we show that there
are several interesting qualitative differences away from these two limits. In
particular, the tunneling model introduces an additional conductance peak at
the energy corresponding to the bulk gap of the parent superconductor. By
employing a combination of analytical methods at zero temperature and numerical
methods at finite temperature, we show that the tunneling model of the
proximity effect reproduces many more of the qualitative features that are seen
experimentally in such a nanowire system.