Proximity effect at superconducting Sn-Bi2Se3 interface

TL;DR

This study explores the conductance properties of Sn-Bi2Se3 interfaces at very low temperatures, revealing anomalies that suggest the formation of a proximity-effect-induced chiral superconducting phase at the interface.

Contribution

It provides experimental evidence of a proximity-induced chiral superconducting phase at the Sn-Bi2Se3 interface through conductance measurements and analysis.

Findings

Observation of a smaller superconducting gap distinct from Sn

Detection of a zero-bias conductance peak at low temperatures

Evidence supporting proximity-effect-induced chiral superconductivity

Abstract

We have investigated the conductance spectra of Sn-Bi2Se3 interface junctions down to 250 mK and in different magnetic fields. A number of conductance anomalies were observed below the superconducting transition temperature of Sn, including a small gap different from that of Sn, and a zero-bias conductance peak growing up at lower temperatures. We discussed the possible origins of the smaller gap and the zero-bias conductance peak. These phenomena support that a proximity-effect-induced chiral superconducting phase is formed at the interface between the superconducting Sn and the strong spin-orbit coupling material Bi2Se3.