In altermagnets, time-reversal symmetry breaking spin-polarizes electronic states, while total magnetization remains zero. In addition, at altermagnetic surfaces Rashba-spin orbit coupling is activated due to broken inversion symmetry, introducing a competing spin-momentum locking interaction. Here we show that their interplay leads to the formation of complex, chiral spin textures that offer novel, non-linear spin-to-charge conversion properties. Whereas altermagnetic order suppresses the canonical linear in-plane Rashba-Edelstein response, we establish the presence of an \textit{anomalous} transversal Edelstein effect for planar applied electric and magnetic field, or alternatively, an in-plane magnetization. Additionally, we predict a purely electric-field-driven non-linear out-of-plane magnetization. We compute the anomalous response within a general altermagnet d-wave model, with parameters extracted from the ab-initio electronic structure of an altermagnetic bilayer. Our results suggest altermagnetic surfaces as a promising platform for unconventional spintronic functionalities.
@article{arxiv.2410.18036,
title = {Non-linear anomalous Edelstein response at altermagnetic interfaces},
author = {Mattia Trama and Irene Gaiardoni and Claudio Guarcello and Jorge I. Facio and Alfonso Maiellaro and Francesco Romeo and Roberta Citro and Jeroen van den Brink},
journal= {arXiv preprint arXiv:2410.18036},
year = {2026}
}