Spin Hall magnetoresistance at the altermagnetic insulator/Pt interface
Miina Leiviskä, Reza Firouzmandi, Kyo-Hoon Ahn, Peter Kubaščik, Zbynek Soban, Satya Prakash Bommanaboyena, Christoph Müller, Dominik Kriegner, Sebastian Sailler, Michaela Lammel, Kranthi Kumar Bestha, Libor Šmejkal, Jakub Zelezny, Anja U. B. Wolter, Monika Scheufele, Johanna Fischer, Matthias Opel, Stephan Geprägs, Matthias Althammer, Bernd Büchner, Tomas Jungwirth, Lukáš Nádvorník, Sebastian T. B. Goennenwein, Vilmos Kocsis, Helena Reichlová
公開日: 2025/1/31
Abstract
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, Ba$_2$CoGe$_2$O$_7$. 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 Ba$_2$CoGe$_2$O$_7$ interface.