Giant intrinsic orbital Hall effects in weakly spin-orbit coupled metals*

Recently, it was proposed that the intrinsic orbital Hall effect (OHE) can emerge from momentum-space orbital texture in centrosymmetric materials [1]. In searching for real materials with strong OHE, we investigate the intrinsic OHE in metals with small spin-orbit coupling (SOC) in face-centered cubic (Al, Mn, and Ni) and body-centered cubic structures (Li, V, Cr, and Mn). We find that these materials can have the giant orbital Hall conductivities (OHCs) ∼ 10³ − 10⁴ (h/e)(Ω cm)^-1, which are comparable or larger than spin Hall conductivity (SHC) of Pt. We also show SHCs in these materials are sizable and the spin Hall angles may be of the order of 0.1, although SHCs are smaller than OHCs due to small SOC. We discuss implications on recent spin-charge interconversion experiments on materials having small SOC.

[1] Go et al., Phys. Rev. Lett. 121, 086602 (2018)