Highly efficient spin current source using BiSb topological insulator/NiO bilayers

BiSb is a topological insulator with both giant spin Hall effect and high electrical conductivity, which are important for ultralow power spin-orbit-torque magnetoresistive random access memory. However, when a ferromagnetic (FM) thin film is deposited on top of BiSb, large surface roughness and diffusion of Sb out of the BiSb layer into the FM layer results in a much smaller effective spin Hall angle theta SHeff.

Automated summary

BiSb is a topological insulator with both a massive spin Hall effect and high electrical conductivity, which are essential for ultralow power spin-orbit-torque magnetoresistive random access memory. However, when a ferromagnetic (FM) thin film is deposited on top of a BiSb layer, the presence of large surface roughness and Sb diffusion into the FM film significantly reduces the effective spin Hall angle, θSHeff.