# Transport signatures of topological superconductivity in a proximity-coupled nanowire

## TL;DR

This paper compares two models of superconductivity in a nanowire with spin-orbit coupling and magnetic field, revealing qualitative differences in conductance features and aligning more closely with experimental observations.

## Contribution

It demonstrates that the tunneling model of proximity-induced superconductivity captures more experimental features than the simplified model where superconductivity is assumed directly.

## Key findings

- Tunneling model introduces an additional conductance peak at the bulk superconductor gap.
- Qualitative differences between models are significant away from low-energy and weak coupling limits.
- Tunneling model aligns better with experimental conductance measurements.

## 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.