Spin Current Generation as a Nonequilibrium Kondo Effect in a Spin-orbit Mesoscopic Interferometer

TL;DR

This paper predicts a novel nonequilibrium spin-dependent current in a quantum dot ring with Rashba spin-orbit coupling, arising from the interplay of Kondo physics and spin-orbit effects without magnetic fields.

Contribution

It introduces a new nonequilibrium correlation effect linking Kondo physics and spin phenomena in nonmagnetic systems with spin-orbit coupling.

Findings

Large spin-dependent current predicted under nonequilibrium conditions

Effect depends on Rashba spin-orbit interaction and Kondo effect

Phenomenon vanishes without interaction or finite bias

Abstract

We study nonequilibrium generation of spin-dependent transport through a single-level quantum dot embedded in a ring with the Rashba spin-orbit coupling. We consider nonmagnetic systems, involving no magnetic field nor ferromagnetic leads. It is theoretically predicted that large spin-dependent current occurs as a combined effect of the Rashba spin-orbit interaction, the Kondo effect, and nonequilibrium effect, without using magnetic field or material. The phenomenon is viewed as a new nonequilibrium correlation effect that disappears when either interaction or finite bias is absent. We show how the Kondo physics is connected with such emergent spin phenomenon by employing the finite interaction slave-boson approach.