Relativistic and Dynamic Fingerprints of Chiral Damping in Chiral Antiferromagnets

Chiral damping (CD) is a nonlocal form of magnetic dissipation that arises in systems with strong spin–orbit coupling and broken structural inversion symmetry. It originates from damping terms linear in the magnetization gradients (Lifshitz invariants) - the dissipative analogue of the Dzyaloshinskii–Moriya interaction - and depends sensitively on the chirality and width of magnetic textures. While its presence has been established in ferromagnets, its influence on antiferromagnetic textures has remained unexplored. Here, we present the first comprehensive theoretical study of CD in chiral antiferromagnets, revealing its distinct effects on domain-wall (DW) dynamics and relativistic behavior. We show that asymmetric CD between sublattices produces off-diagonal components in the DW mass tensor, thereby coupling translational and rotational modes of motion. When an AC gate voltage is used to modulate the Rashba spin–orbit interaction, symmetric and asymmetric components of CD induce oscillations in the DW velocity and tilt angle, respectively, and can even trigger switching of the DW chirality. These effects are fully captured by analytical calculations and confirmed by numerical simulations. Moreover, analysis of the antiferromagnetic resonance (AFR) linewidth reveals a pronounced broadening under strong driving conditions, predominantly governed by CD. This provides an experimentally feasible pathway to measure and quantify CD. Together, these findings establish clear dynamical and relativistic signatures of CD in AFMs and open routes toward energy-efficient, reconfigurable spintronic devices based on the active control of magnetic chirality.