Giant Spin-to-Charge Conversion by Tailoring Magnetically Proximitized Topological Dirac Semimetal

Abstract

The role of magnetic proximity on topological surface states (TSSs) and spin-to-charge conversion efficiency is studied in Fe/topological Dirac semimetal $\alpha$-Sn heterostructures. As $\alpha$-Sn thickness increases (9-38 nm), the damping constant of Fe peaks at 25 nm and then decreases. Theoretical modeling links this to long-range magnetic proximity effects (MPE) that suppress TSSs at the Fe/$\alpha$-Sn interface while opening an exchange gap at the opposite interface. At 25 nm, we achieve an inverse Edelstein length of -3.1$\pm$1.0 nm, one of the highest values at room temperature, highlighting MPE's importance in spintronics.