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

TL;DR

This paper investigates the spin and orbital Edelstein effects in a bilayer Rashba system, revealing that orbital magnetization can dominate and that the response can be tuned or reversed by adjusting layer parameters.

Contribution

It introduces a comprehensive study of both spin and orbital Edelstein effects in bilayer systems using modern orbital magnetization theory and Boltzmann transport, highlighting tunability and dominance of orbital effects.

Findings

Orbital Edelstein effect can surpass spin effect in magnitude.

Edelstein response is tunable and can be reversed by layer parameter adjustments.

Sign change in orbital polarization indicates layer state interchange.

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 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 work, 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 relaxation-time approximation. We found that the orbital effect can be significantly larger than the spin effect, depending on the model parameters. Furthermore, the 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.