Enhanced spin Hall ratio in two-dimensional III-V semiconductors

Spin Hall effect (SHE) plays a critical role in spintronics since it can convert charge current to spin current. Using state-of-the-art ab initio calculations including quadrupole and spin-orbit coupling, the charge and spin transports have been investigated in pristine and doped two-dimensional (2D) III-V semiconductors. Valence bands induce a strong scattering which limits charge conductivity in the hole-doped system, where spin Hall conductivity is enhanced by the spin-orbit splitting, yielding an ultrahigh spin Hall ratio 𝜉≈0.9 in GaAs monolayer at room temperature.