Spin flop and crystalline anisotropic magnetoresistance in CuMnAs

TL;DR

This paper demonstrates the manipulation and detection of antiferromagnetic order in CuMnAs thin films through spin-flop switching and spin reorientation, using various spectroscopic and magnetometric techniques.

Contribution

It provides new experimental insights into spin-flop and spin reorientation phenomena in CuMnAs, advancing understanding of antiferromagnetic spintronics.

Findings

Spin-flop switching observed in uniaxial CuMnAs films.

Continuous spin reorientation in biaxial CuMnAs films.

Quantitative material parameters derived from measurements.

Abstract

Recent research works have shown that the magnetic order in some antiferromagnetic materials can be manipulated and detected electrically, due to two physical mechanisms: Neel-order spin-orbit torques and anisotropic magnetoresistance. While these observations open up opportunities to use antiferromagnets for magnetic memory devices, different physical characterization methods are required for a better understanding of those mechanisms. Here we report a magnetic field induced rotation of the antiferromagnetic Neel vector in epitaxial tetragonal CuMnAs thin films. Using soft x-ray magnetic linear dichroism spectroscopy, x-ray photoemission electron microscopy, integral magnetometry and magneto-transport methods, we demonstrate spin-flop switching and continuous spin reorientation in antiferromagnetic films with uniaxial and biaxial magnetic anisotropies, respectively. From field-dependent measurements of the magnetization and magnetoresistance, we obtain key material parameters including the anisotropic magnetoresistance coefficients, magnetocrystalline anisotropy, spin-flop and exchange fields.