Observation of isosceles triangular electronic structure around excess iron atoms in Fe$_{1+\delta}$Te

TL;DR

This study uses scanning tunneling microscopy to reveal a unique isosceles triangular electronic pattern around excess iron atoms in Fe$_{1+elta}$Te, linking local electronic structure to magnetic and structural symmetries.

Contribution

It uncovers a novel isosceles triangular electronic structure around excess Fe atoms, connecting local electronic features with magnetic and structural symmetries in Fe$_{1+elta}$Te.

Findings

Identified a distinct isosceles triangular electronic pattern.

Linked the pattern's symmetry to magnetic and structural properties.

Provided insights into the role of excess Fe atoms in iron-chalcogenides.

Abstract

We present scanning tunneling microscopy and spectroscopy studies around an individual excess Fe atom, working as a local perturbation, in the parent material of the iron-chalcogenide superconductor Fe$_{1+\delta}$Te. Spectroscopic imaging reveals a novel isosceles triangular electronic structure around the excess Fe atoms. Its spatial symmetry reects the underlying bicollinear antiferromagnetic spin state and the structural monoclinic symmetry. These findings provide important clues to understand the role of the excess Fe atoms, which complicate the understanding of the phenomena occurring in iron-chalcogenide materials.