Spin transport at the multiferroic altermagnet/heavy metal interfaces
Miina Leiviskä, Institute of Physics, Czech Academy of Sciences, Prague, Czechia
Tursday 7 May 2026, 12 PM
ICMAB - Sala d'Actes Carles Miravitlles
Abstract
Spin Hall magnetoresistance (SMR) is a magnetoresistive effect present in bilayers comprising of a magnet (here insulating) and a heavy metal. It relies on the concerted action of spin Hall effect, inverse spin Hall effect, and dissipation of spin accumulation at the interface. The dissipation of the spin accumulation occurs via various channels, including spin-transfer torque and magnon-mediated spin current transfer. Altermagnets are a new class of collinear compensated magnets with a unique anisotropic spin ordering with characteristic spin-degenerate nodes and alternating even-parity spin polarization that breaks the time-reversal symmetry. In this work, we present a set of SMR measurements in heterostructures of Pt and an insulating and ferroelectric altermagnet candidates Ba2CoGe2O7 and Sr2CoSi2O7. We will first detail the fabrication of devices for SMR experiments on bulk crystals and then discuss characteristic SMR features of the systems under study. We show that in both systems the SMR ratio is unexpectedly large and shows anisotropy depending on in which crystal direction the current is applied. We systematically rule out device-to-device variations, magnetic domains, and magnetocrystalline anisotropy as the main origin of this current-direction anisotropy of the SMR ratio, and also address the possible effects of ferroelectric polarization on the SMR. Finally, we will suggest mechanisms through which the crystal symmetries that characterize the altermagnetic phase of Ba2CoGe2O7 and Sr2CoSi2O7 could give rise to the observed anisotropy.
Short bio
Miina Leiviskä is a Marie Skłodowska-Curie Postdoctoral Fellow at the Institute of Physics of the Czech Academy of Sciences, where she works on spin transport in altermagnetic multiferroic materials. She completed her PhD in 2023 at the Spintec Laboratory, focusing on compensated spin structures and spin textures. Her broader research interests lie in altermagnetic spintronics, with a particular emphasis on how unconventional magnetic order can be harnessed for next-generation spin-based technologies.
Hosted by Ignasi Fina, from the FOXEM group (Materials for Electronics Research Line)
>>If you want to meet the speaker, please contact the host at This email address is being protected from spambots. You need JavaScript enabled to view it..
