Probing pair-breaking mechanisms in proximity-induced hybrid superconducting interfaces

TL;DR

This paper investigates the mechanisms that break or preserve pairing in hybrid superconducting interfaces with strong spin-orbit materials, providing a phenomenological model to understand how these effects influence tunneling conductance under magnetic fields.

Contribution

It introduces a new phenomenological framework to characterize pair-breaking mechanisms in hybrid superconducting interfaces, especially considering spin-orbit effects and magnetic field influences.

Findings

Conductance peak pinning at zero bias persists over larger fields.

Varying spin-orbit scattering affects conductance peak behavior.

Weak peak splitting observed at higher magnetic fields.

Abstract

Understanding depairing effects in a hybrid-superconducting interface utilizing high spin-orbit materials such as topological insulators or 1D semiconducting nanowires is becoming an important research topic in the study of proximity-induced superconductivity. Experimentally, proximity-induced superconductivity is found to suppress at much lower magnetic fields compared to the superconducting layer without a good understanding of its cause. Here, we provide a phenomenological tool to characterize different pair-breaking mechanisms, the ones that break or preserve time reversal symmetry, and show how they affect the differential tunneling conductance response. Importantly, we probe the properties of the SC layer at the hybrid interface and observe conductance peak pinning at zero bias in a larger field range with eventual signs of weak peak splitting. Further, the effect of varying the spin-orbit scattering and the Lande g-factor in tuning the conductance peaks show interesting trends.