Long-Time Magnetic Relaxation in Antiferromagnetic Topological Material EuCd$_2$As$_2$

TL;DR

This study reveals a significant long-time magnetic relaxation in EuCd$_2$As$_2$, an antiferromagnetic topological material, with susceptibility increasing over hours, influenced by temperature and magnetic field, indicating complex magnetic dynamics.

Contribution

First detailed observation of long-time magnetic relaxation in EuCd$_2$As$_2$, highlighting anisotropic and temperature-dependent behavior in a magnetic topological material.

Findings

Magnetic susceptibility increases by ~10% over 14 hours at 5 K.

Relaxation is anisotropic and varies with temperature and magnetic field.

Results suggest complex magnetic dynamics affecting electronic properties.

Abstract

Magnetic topological materials have attracted much attention due to the correlation between topology and magnetism. Recent studies suggest that EuCd$_2$As$_2$ is an antiferromagnetic topological material. Here by carrying out thorough magnetic, electrical and thermodynamic property measurements, we discover a long time relaxation of the magnetic susceptibility in EuCd$_2$As$_2$. The (001) in-plane magnetic susceptibility at 5 K is found to continuously increase up to $\sim$10% over the time of $\sim$14 hours. The magnetic relaxation is anisotropic and strongly depends on the temperature and the applied magnetic field. These results will stimulate further theoretical and experimental studies to understand the origin of the relaxation process and its effect on the electronic structure and physical properties of the magnetic topological materials.