Dirac nodal line metal for topological antiferromagnetic spintronics

TL;DR

This paper predicts that the antiferromagnetic metal MnPd₂ can electrically control Dirac nodal lines via Ne9el spin-orbit torque, enabling topological spintronic applications at room temperature.

Contribution

It introduces MnPd₂ as a practical room-temperature AFM material for topological spintronics, demonstrating control of Dirac nodal lines through Ne9el vector reorientation.

Findings

Reorientation of Ne9el vector switches between degenerate and gapped states.

Spin Hall conductivity varies with Ne9el vector orientation.

Proposed device can detect the effect via spin-orbit torque measurements.

Abstract

Topological antiferromagnetic (AFM) spintronics is an emerging field of research, which exploits the N\'eel vector to control the topological electronic states and the associated spin-dependent transport properties. A recently discovered N\'eel spin-orbit torque has been proposed to electrically manipulate Dirac band crossings in antiferromagnets; however, a reliable AFM material to realize these properties in practice is missing. Here, we predict that room temperature AFM metal MnPd$_{2}$ allows the electrical control of the Dirac nodal line by the N\'eel spin-orbit torque. Based on first-principles density functional theory calculations, we show that reorientation of the N\'eel vector leads to switching between the symmetry-protected degenerate state and the gapped state associated with the dispersive Dirac nodal line at the Fermi energy. The calculated spin Hall conductivity strongly depends on the N\'eel vector orientation and can be used to experimentally detect the predicted effect using a proposed spin-orbit torque device. Our results indicate that AFM Dirac nodal line metal MnPd$_{2}$ represents a promising material for topological AFM spintronics.