Generation of current vortex by spin current in Rashba systems

TL;DR

This paper demonstrates how spin injection in Rashba systems can generate a charge-current vortex, revealing spin-orbit interactions and angular momentum conversion, with implications for future experimental detection.

Contribution

The study introduces large-scale time-dependent density-matrix renormalization-group simulations to show vortex generation via spin injection in Rashba systems, highlighting angular momentum conservation effects.

Findings

Charge-current vortex generated by spin injection.

Conversion between spin and orbital angular momentum.

Predicted electromagnetic field associated with the vortex.

Abstract

Employing unbiased large-scale time-dependent density-matrix renormalization-group simulations, we demonstrate the generation of a charge-current vortex via spin injection in the Rashba system. The spin current is polarized perpendicular to the system plane and injected from an attached antiferromagnetic spin chain. We discuss the conversion between spin and orbital angular momentum in the current vortex that occurs because of the conservation of the total angular momentum and the spin-orbit interaction. This is in contrast to the spin Hall effect, in which the angular-momentum conservation is violated. Finally, we predict the electromagnetic field that accompanies the vortex with regard to possible future experiments.