Temperature dependence of surface superconductivity in t-PtBi$_2$

TL;DR

This study investigates the temperature dependence of surface superconductivity in t-PtBi$_2$, revealing a large superconducting gap that closes near 45K, supporting its potential as a high-temperature topological superconductor.

Contribution

The paper provides the first detailed temperature evolution of the superconducting gap in t-PtBi$_2$ using scanning tunneling spectroscopy, confirming high-temperature surface superconductivity.

Findings

Superconducting gap of ~9 meV at low temperatures

Gap closes around 45 K, indicating high T_c-like superconductivity

Supports t-PtBi$_2$ as a candidate for topological surface superconductivity

Abstract

The Weyl semimetal trigonal PtBi$_2$ has recently been identified as a promising candidate material for intrinsic topological surface superconductivity emerging from the Fermi arc states of the material with a sizeable superconducting gap. We report the temperature evolution of the superconducting excitation spectrum using scanning tunneling spectroscopy in the range of $8-45\,$K. A large low-temperature gap in the order of $\Delta \approx 9\,$meV and a closing of the gap around $T_c \approx 45\,$K is observed. Thus, our results confirm the previously indicated high $T_c$-like superconductivity in t-PtBi$_2$.