Strain engineering of the intrinsic spin Hall conductivity in a SrTiO3 quantum well

The intrinsic spin Hall conductivity of a two-dimensional gas confined to ${\mathrm{SrTiO}}₃$, such as occurs at an ${\mathrm{LaAlO}}₃/{\mathrm{SrTiO}}₃$ interface, is calculated from the Kubo formula. The effect of strain in the [001] and the [111] directions is incorporated into a full tight-binding Hamiltonian for a quantum well with a [001] growth direction. We show that the spin-charge conversion ratio can be significantly altered through the strain and gate voltage by tuning the chemical potential. The strain direction is also a significant factor in the spin Hall response, as this direction affects the alignment of the conduction bands.