Intrinsic spin and orbital Hall effects in heavy-fermion systems

Abstract

We study the intrinsic spin Hall effect (SHE) based on the orbitally degenerate periodic Anderson model, which is an effective model for heavy fermion systems. In the very low resistivity regime, the magnitude of the intrinsic spin Hall conductivity (SHC) is estimated as $2000\ensuremath{\sim}3000\ensuremath{\hbar}\text{ }{e}^{\ensuremath{-}1}\text{ }{\ensuremath{\Omega}}^{\ensuremath{-}1}\text{ }{\text{cm}}^{\ensuremath{-}1}$; it is about ten times larger than that in Pt. Its sign is negative (positive) in Ce (Yb) compound systems with ${f}^{1}$ $({f}^{13})$ configuration. Interestingly, the obtained expression for the SHC depends only on the density of conduction electrons but is independent of the strength of the $c\text{\ensuremath{-}}f$ mixing potential and the mass-enhancement factor. The origin of the huge SHE is the spin-dependent Berry phase induced by the complex $f$-orbital wave function, which we call the ``orbital Aharonov-Bohm effect.''