Atomic-Scale Visualization of a Cascade of Magnetic Orders in the Layered Antiferromagnet $GdTe_{3}$

TL;DR

This study uses spin-polarized scanning tunneling microscopy to directly visualize and characterize the complex cascade of magnetic orders in the layered antiferromagnet GdTe3, revealing the interplay between charge density waves and magnetic phases.

Contribution

It provides the first direct imaging of magnetic order parameters in GdTe3 and elucidates the relationship between charge density waves and magnetic transitions.

Findings

Identified a striped antiferromagnetic phase below 7 K with doubled periodicity.

Discovered a spin density wave between 7 and 12 K matching the CDW periodicity.

Supported phase stability with a Landau free energy model.

Abstract

$GdTe_{3}$ is a layered antiferromagnet which has attracted attention due to its exceptionally high mobility, distinctive unidirectional incommensurate charge density wave (CDW), superconductivity under pressure, and a cascade of magnetic transitions between 7 and 12 K, with as yet unknown order parameters. Here, we use spin-polarized scanning tunneling microscopy to directly image the charge and magnetic orders in $GdTe_{3}$. Below 7 K, we find a striped antiferromagnetic phase with twice the periodicity of the Gd lattice and perpendicular to the CDW. As we heat the sample, we discover a spin density wave with the same periodicity as the CDW between 7 and 12 K; the viability of this phase is supported by our Landau free energy model. Our work reveals the order parameters of the magnetic phases in $GdTe_{3}$ and shows how the interplay between charge and spin can generate a cascade of magnetic orders.