Phonon-renormalized noncollinear RKKY interaction in Rashba altermagnets
Phys. Rev. B 114, 204403 – Published 1 October, 2026
DOI: https://doi.org/10.1103/9yd4-qyzj
Abstract
Altermagnets, characterized by time-reversal symmetry breaking without net magnetization and momentum-dependent spin-split bands, offer a promising platform for spintronics due to their anisotropic spin textures and potential for tunable magnetic interactions. Here, we theoretically investigate the slow phonon-renormalized Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in two-dimensional Rashba -wave altermagnets, incorporating arbitrary Rashba spin-orbit coupling (RSOC) strength and spin-dependent static-Holstein electron-phonon coupling (EPC). Using a continuum model Hamiltonian that captures altermagnetic anisotropy, RSOC, and adiabatic lattice distortions, we compute the noncollinear RKKY exchange tensor via second-order perturbation theory and numerical momentum-space integration. Our results reveal that static lattice distortions provide a versatile tuning knob for engineering the magnitude, anisotropy, and chirality of RKKY couplings. Moderate EPC suppresses long-range coherence while inducing component-specific phase shifts and sign reversals, particularly in Dzyaloshinskii-Moriya (DM) and compasslike terms. Systematic parameter scans demonstrate enhanced oscillatory complexity with altermagnetic order, RSOC, and doping, establishing slow phonons as a practical route to dynamically control ferromagnetic/antiferromagnetic alignments and DM chiralities in altermagnet-based heterostructures.