A personal spin on spin currents

This article contains my personal account on how I got interested in spin transport phenomena, which ultimately resulted in investigating multiple facets of spin–orbit torques, as well as magnetization dynamics. Originally this research focused on questions that seemed rather academic with little relevance to applications. But over time it developed into one of the key research areas for modern spintronic devices. This journey started off with investigating spin polarized charge currents, later focused on pure spin currents, and ultimately explored spin waves (magnons) as the potential carriers of spin information. Most of this work was performed in the Magnetic Films group of the Argonne National Laboratory, which for more than three decades used to be one of the world-leading places for magnetism research. • This manuscript chronicles research in the Magnetic Film group at Argonne. • Non-local transport enabled the exploration of pure spin currents. • Spin Hall effects morphed from academic curiosity to a key spintronics phenomenon. • Spin waves emerged as complementary types of spin currents. • Current open questions include structural chirality and orbital angular momentum.