Effective Dresselhaus and Rashba spin-orbit interactions in narrow quantum wells

Rashba and linear Dresselhaus interactions are believed to yield dominant contribution to the spin splitting of two-dimensional electrons in the quantum wells based on A$_3$B$_5$ compounds. We show that the interfacial spin-orbit interaction significantly renormalizes the value of the corresponding Rashba ($\alpha_{SIA}$) and Dresselhaus ($\alpha_{BIA}$) parameters. For this purpose, we solve the effective mass equation in a quantum well supplemented by the original boundary conditions on the atomically sharp interfaces and calculate the interfacial contributions to $\alpha_{SIA}$ and $\alpha_{BIA}$. Our results explain a considerable spread in the experimental data on spin-orbit parameters in GaAs/AlGaAs quantum wells. We also demonstrated that the non-equivalence of the interfaces leads to the anisotropy of the spin splitting even in quantum wells with zero average electric field.