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

The role of magnetic proximity on topological surface states (TSSs) and spin-to-charge conversion efficiency is studied in Fe/topological Dirac semimetal α-Sn heterostructures. As α-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/ α-Sn interface while opening an exchange gap at the opposite interface. At 25 nm, we achieve an inverse Edelstein length of-3.1 plus or minus 1.0 nm, one of the highest values at room temperature, highlighting MPE's importance in spintronics.