Spin Hall effect in semiconductor heterostructures with cubic Rashba spin-orbit interaction

We study the spin Hall effect in systems with weak cubic Rashba spin-orbit interaction. To this end we derive particle and spin diffusion equations and explicit expressions for the spin-current tensor in the diffusive regime. We discuss the impact of electric fields on the Green's functions and the diffusion equations and establish a relationship between the spin-current tensor and the spin diffusion equations for the model under scrutiny. We use our results to calculate the edge spin-accumulation in a spin Hall experiment and show that there is also a Hall-like contribution to the electric current in such systems.