Coulomb Drag and Spin Coulomb Drag in the presence of Spin-orbit Coupling

TL;DR

This paper calculates charge and spin Coulomb drag resistivities in systems with Rashba spin-orbit coupling, revealing small enhancements in the ballistic regime and no change in the diffusive regime due to disorder effects.

Contribution

It provides analytical expressions for Coulomb drag resistivities considering spin-orbit coupling, highlighting the regime-dependent effects on resistivity.

Findings

Small enhancement of resistivities in the ballistic regime due to spin-orbit interaction.

No change in Coulomb drag resistivity in the diffusive regime caused by disorder.

Analytical formulas derived for resistivities with spin-orbit coupling.

Abstract

Employing diagrammatic perturbation theory, we calculate the (charge) Coulomb drag resistivity $\rho_D$ and spin Coulomb drag resistivity $\rho_{\uparrow\downarrow}$ in the presence of Rashba spin-orbit coupling. Analytical expressions for $\rho_D$ and $\rho_{\uparrow\downarrow}$ are derived, and it is found that spin-orbit interaction produces a small enhancement to $\rho_D$ and $\rho_{\uparrow\downarrow}$ in the ballistic regime while $\rho_D$ is unchanged in the diffusive regime. This enhancement in the ballistic regime is attributed to the enhancement of the nonlinear susceptibility (i.e. current produced through the rectification of the thermal electric potential fluctuations in the passive layer) while the lack of enhancement in the diffusive regime is due to the suppression by disorder.