Large spontaneous Hall effect with flexible domain control in an antiferromagnetic material TaMnP

TL;DR

This paper demonstrates a large anomalous Hall effect in the antiferromagnetic material TaMnP, controllable via small magnetic fields, with potential applications in antiferromagnetic memory devices.

Contribution

It reveals a significant anomalous Hall conductivity in TaMnP driven by spin-orbit interactions and domain control, despite its small net magnetization, advancing AF spintronics.

Findings

Large AHC of ~360-370 Ω^{-1}cm^{-1} observed in TaMnP.

AF domain switching controllable by magnetic fields along all axes.

First-principles calculations highlight the role of Ta 5d electrons in Berry curvature enhancement.

Abstract

Antiferromagnets without parity-time ($\mathcal{PT}$) symmetry offer novel perspectives in the field of functional magnetic materials. Among them, those with ferromagnetic-like responses are promising candidates for future applications such as antiferromagnetic (AF) memory; however, examples showing large effects are extremely limited. In this study, we show that the orthorhombic system TaMnP exhibits a large anomalous Hall conductivity (AHC) $\sim360-370$ $\Omega^{-1}$cm$^{-1}$ in spite of the small net magnetization $\sim10^{-2}$ $\mu_B$/Mn. Our neutron scattering experiment and the observation of the AH effect indicated that a magnetic structure of TaMnP was dominated by an AF component represented by $B_{3g}$ with the propagation vector $q=0$. Furthermore, we confirmed that the obtained AHC is among the largest observed in AF materials at zero fields. Additionally, our first-principles calculations revealed that the spin-orbit interaction originating in the nonmagnetic Ta-$5d$ electrons significantly contributes to enhancing Berry curvatures in the momentum space. We found that the magnetic fields along all the crystal axes triggered the AF domain switching, indicating the possibility of controlling the AF domain using the small net magnetization, which is symmetrically different.