Altermagnets can convert charge currents into spin currents through the so-called spin-splitter effect. This theory paper gives a unified description of that effect and its inverse in diffusive hybrid devices, based on drift–diffusion equations for coupled charge and spin and on general boundary conditions, expressed in experimentally accessible parameters.

The authors show that an injected spin accumulation produces a measurable transverse voltage in the altermagnet. Motivated by a recent experiment, they also model a nonlocal spin valve in which an altermagnetic strip injects spin into a normal metal, accounting for the main experimental findings, and analyse spin precession through the Hanle effect. QMAT's Tim Kokkeler of the University of Jyväskylä wrote the paper with colleagues at Universidad de la República in Uruguay and at CFM and DIPC in San Sebastián.

Image: QMAT