Mystery of superconductivity in FeTe films and the role of neighboring layers

TL;DR

This paper reviews the mysterious emergence of superconductivity in FeTe films, emphasizing the influence of neighboring telluride layers and stoichiometry, offering new insights into the mechanisms enabling superconductivity in this system.

Contribution

It provides the first comprehensive review linking neighboring layers to FeTe superconductivity and demonstrates the importance of stoichiometry control for stabilizing superconductivity.

Findings

Telluride neighboring layers are key to superconductivity in FeTe films.

Stoichiometric Te content stabilizes superconductivity.

Insights into manipulating topological superconductivity in FeTe heterostructures.

Abstract

Since the discovery of superconductivity in the Fe(Te,Se) system, it has been a general consensus that the end member of FeTe is not superconducting. Nonetheless, in recent years, there have been reports of superconducting FeTe films, but the origin of their superconductivity remains mysterious. Here, we provide the first comprehensive review of all the reported FeTe films regarding the relationship between their superconductivity and neighboring layers. Based on this review, we show that telluride neighboring layers are the key to superconducting FeTe films. Then, with additional new studies, we show that stoichiometric Te content, which can be readily achieved in FeTe films with the assistance of neighboring telluride layers, might be crucial to stabilizing the superconductivity in this system. This work provides insights into the underlying mechanism behind superconductivity in FeTe films and sheds light on the critical role of neighboring layers and stoichiometry control toward manipulating topological superconductivity in FeTe heterostructures.