Signature of proximity induced triplet superconductivity in junctions made of the doped topological insulator $\rm Bi_2Se_3$ and the s-wave superconductor NbN

TL;DR

This study provides evidence of proximity-induced triplet superconductivity in doped topological insulator $ m Bi_2Se_3$ when interfaced with s-wave superconductor NbN, based on conductance spectra analysis and tunneling model fitting.

Contribution

It demonstrates that the triplet $p_x+ip_y$ pair potential best fits the conductance data, indicating the presence of triplet superconductivity in $ m Bi_2Se_3$ near the interface.

Findings

Zero bias conductance peaks observed

Triplet $p_x+ip_y$ pairing model fits data well

Evidence of proximity-induced triplet superconductivity

Abstract

Thin film junctions and bilayers of the doped topological insulator $\rm Bi_2Se_3$ and the s-wave superconductor NbN were found to exhibit conductance spectra with prominent zero bias and coherence peaks. Various tunneling models with different pair potentials have failed to fit our data, except for the triplet $p_x+ip_y$ pair potential, which breaks time reversal symmetry, but yielded reasonably good fits. This provides evidence for proximity induced triplet superconductivity in the $\rm Bi_2Se_3$ layer near the interface with the NbN film.