Spin and orbital Edelstein effect in a bilayer system with Rashba interaction

Abstract

The spin Edelstein effect has proven to be a promising phenomenon to generate spin polarization from a charge current in systems without inversion symmetry. In recent years, a current-induced orbital magnetization, called the orbital Edelstein effect, has been predicted for various systems with broken inversion symmetry, using the atom-centered approximation and the modern theory of orbital magnetization. In this paper, we study the current-induced spin and orbital magnetization for a bilayer system with Rashba interaction, using the modern theory of orbital magnetization and Boltzmann transport theory in the relaxation time approximation. We find that the spin Edelstein effect is significantly larger than the orbital contribution. Furthermore, the orbital Edelstein response can be enhanced, suppressed, and even reversed, depending on the relation of the effective Rashba parameters of each layer. A sign change of the orbital polarization is related to an interchange of the corresponding layer localization of the states.