The resistance of a heavy metal can be modulated by an adjacent magnetic material through the combined effects of the spin Hall effect, inverse spin Hall effect, and dissipation of the spin accumulation at the interface. This phenomenon is known as the spin Hall magnetoresistance. The dissipation of the spin accumulation can occur via various mechanisms, with spin-transfer torque being the most extensively studied. In this work, we report the observation of spin Hall magnetoresistance at the interface between platinum and an insulating altermagnetic candidate, Ba2CoGe2O7. Our findings reveal that this heterostructure exhibits a relatively large spin Hall magnetoresistance signal, which is anisotropic with respect to the crystal orientation of the current channel. We explore and rule out several potential explanations for this anisotropy and propose that our results may be understood in the context of the anisotropies of the spin current channels across the Pt/altermagnetic Ba2CoGe2O7 interface.
@article{arxiv.2501.19198,
title = {Spin Hall magnetoresistance at the altermagnetic insulator/Pt interface},
author = {Miina Leiviskä and Reza Firouzmandi and Kyo-Hoon Ahn and Peter Kubaščik and Zbynek Soban and Satya Prakash Bommanaboyena and Christoph Müller and Dominik Kriegner and Sebastian Sailler and Michaela Lammel and Kranthi Kumar Bestha and Libor Šmejkal and Jakub Zelezny and Anja U. B. Wolter and Monika Scheufele and Johanna Fischer and Matthias Opel and Stephan Geprägs and Matthias Althammer and Bernd Büchner and Tomas Jungwirth and Lukáš Nádvorník and Sebastian T. B. Goennenwein and Vilmos Kocsis and Helena Reichlová},
journal= {arXiv preprint arXiv:2501.19198},
year = {2025}
}