# Andreev spectroscopy of the triplet superconductivity state in Bi/Ni bilayer system

## TL;DR

This paper investigates the Andreev spectroscopy of different superconducting states in Bi/Ni bilayers, identifying the ABM state mixed with pz-wave as the best explanation for experimental results.

## Contribution

It demonstrates that only the ABM state combined with pz-wave pairing can explain both point contact and THz spectroscopy experiments in Bi/Ni bilayers.

## Key findings

- ABM state with pz-wave explains experimental data
- Surface states induce conductance peaks near zero energy
- Different pairing states have distinct spectroscopic signatures

## Abstract

We calculate the Andreev spectroscopy between a ferromagnetic lead and Bi/Ni bilayer system for three types of superconducting states, including ABM state, ABM state mixing with S-wave state, ABM state mixing with pz-wave state. Among them, ABM state and ABM state mixing with S- wave state can obtain the Andreev conductance consistent with the point contact experiment[G. J. Zhao,et al, arXiv:1810.10403], but failed to explain the experiment of time-domain THz spectroscopy experiment[Prashant Chauhan,et al, Phys. Rev. Lett. 122, 017002(2019)]. Only the ABM state mixing with pz-wave state can explain both experiments. Besides, we reveal the conductance peak near the zero energy is induced by the surface state of the ABM phase. Our work may provides helpful clarification for understanding of recent experiments.