Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

TL;DR

This study introduces a new uniaxial-strain device integrated into a scanning tunneling microscope to manipulate and visualize antiferromagnetic domains at the atomic scale in Fe1+yTe, revealing strain-induced domain transitions.

Contribution

The paper presents a novel experimental setup combining uniaxial strain control with spin-polarized STM to study magnetic domain responses in quantum materials.

Findings

Unstrained Fe1+yTe exhibits bidirectional antiferromagnetic domains.

Applied uniaxial strain transitions domains into a single unidirectional state.

The domain size ranges from 50 to 150 nm.

Abstract

The quest to understand correlated electronic systems has pushed the frontiers of experimental measurements toward the development of new experimental techniques and methodologies. Here we use a novel home-built uniaxial-strain device integrated into our variable temperature scanning tunneling microscope that enables us to controllably manipulate in-plane uniaxial strain in samples and probe their electronic response at the atomic scale. Using scanning tunneling microscopy with spin-polarization techniques, we visualize antiferromagnetic domains and their atomic structure in Fe1+yTe samples, the parent compound of iron-based superconductors, and demonstrate how these domains respond to applied uniaxial strain. We observe the bidirectional antiferromagnetic domains in the unstrained sample, with an average domain size of 50 to 150 nm, to transition into a single unidirectional domain under applied uniaxial strain. The findings presented here open a new direction to utilize a valuable tuning parameter in scanning tunneling microscopy, as well as other spectroscopic techniques, both for tuning the electronic properties as for inducing symmetry breaking in quantum material systems.