Superconductivity in the Bi/Ni bilayer

TL;DR

This paper investigates the potential for p-wave superconductivity in Bi/Ni bilayers, proposing a phonon-mediated mechanism and explaining observed p-wave signals through a theoretical model considering surface states.

Contribution

It provides a theoretical exploration of p-wave superconductivity in Bi/Ni bilayers, suggesting a phonon-mediated mechanism and explaining experimental signals with a simple model.

Findings

Superconductivity in Bi/Ni bilayers is likely phonon-mediated.

p-wave like signals can arise from surface states in the bilayer.

Theoretical model explains surface probe observations.

Abstract

Motivated by the recent observations of possible p-wave superconductivity in the bismuth-nickel (Bi/Ni) bilayer, we explore theoretically the possibilities of realizing p-wave superconductivity in this bilayer. We begin with a literature survey on this system and related materials which have similar superconducting transition temperature. From the survey, the superconducting mechanism in this bilayer system is suggested to be phonon mediated type II superconductivity. A simple model is proposed to explain why the p-wave like Andreev reflection signals are likely to be observed in the surface probe, assuming the strong spin-orbit coupled surface state of Bi thin film is not completely destroyed by the formation of alloys.