A possible superconducting gap signature with filling temperature around 40 K in hexagonal iron telluride islands

TL;DR

This study reports the growth of hexagonal FeTe islands on SrTiO3 with a superconducting-like gap signature near 40 K, challenging the notion that FeTe is non-superconducting and opening avenues for new superconductor exploration.

Contribution

It demonstrates a method to grow atomically flat FeTe islands with a superconducting gap signature, suggesting FeTe can exhibit superconductivity under specific conditions.

Findings

Detected a gap structure with a filling temperature near 40 K.

Observed the gap signature under various experimental conditions.

Proposed FeTe as a potential platform for new superconductors.

Abstract

Superconductivity in the iron-chalcogenide series FeSe-Fe(Te, Se)-FeTe has been restricted to the near neighbor of iron selenide (FeSe), with a general consensus that iron telluride (FeTe) is not superconducting. In this study, we report the method to grow FeTe islands with atomically flat surface and hexagonal lattice on SrTiO3 (001) substrates, in which a gap structure with a gap-filling temperature close to 40 K is detected by scanning tunneling spectroscopy. Such signature is examined under various conditions and reminiscent of a superconducting gap structure. This work might offer a potential platform to explore new superconductors at ambient pressure.