# Damping and Anti-Damping Phenomena in Metallic Antiferromagnets: An ab-initio Study

## TL;DR

This study uses first-principles calculations to analyze damping phenomena in metallic antiferromagnets, revealing the roles of relativistic and exchange components in AFMR linewidth and the effects of current-induced torques.

## Contribution

It provides a detailed ab-initio analysis of AFMR phenomena, distinguishing relativistic and exchange contributions and exploring current-induced torques in metallic antiferromagnets.

## Key findings

- Exchange component dominates at low temperatures.
- Relativistic component linked to spin orbit coupling.
- Current-induced torques influence AFMR linewidth and exchange coupling.

## Abstract

We report on a first principles study of anti-ferromagnetic resonance (AFMR) phenomena in metallic systems [MnX (X=Ir,Pt,Pd,Rh) and FeRh] under an external electric field. We demonstrate that the AFMR linewidth can be separated into a relativistic component originating from the angular momentum transfer between the collinear AFM subsystem and the crystal through the spin orbit coupling (SOC), and an exchange component that originates from the spin exchange between the two sublattices. The calculations reveal that the latter component becomes significant in the low temperature regime. Furthermore, we present results for the current-induced intersublattice torque which can be separated into the Field-Like (FL) and Damping-Like (DL) components, affecting the intersublattice exchange coupling and AFMR linewidth, respectively.