Spin-orbital strain effects in semiconductors

We reconsider spin-orbit contribution to strain effects in semiconductors within six-valence-band k · p model. We demonstrate that standard procedure for including that contribution is generally wrong. Indeed, we show that taking into account the spin-orbital strain term of the effective hamiltonian does not modify the matrix form of the strain model in terms of deformation components. Consequently, part of the spin-orbital strain interaction is formally included in the a, b and d deformation potential parameters of the conventional Bir-Pikus matrix. This result brings into question the parameter values: do they or not take into account that spin-orbital strain contribution? Moreover, the remaining part, which involves the split-off valence band, is included in a form similar to that of Pidgeon-Brown (set up for P_iP_j products) using three additional parameters a_Δ, b_Δ and d_Δ (in place of γ1Δ, γ2Δ and γ3Δ). Following this original approach, we propose new parametrized models for Si, Ge, GaAs and InAs materials. Impacts of spin-orbit contribution are presented for Si, Ge, GaAs and InAs bulk and [001] quantum wells.