Adiabatic pumping through an interacting quantum dot with spin-orbit coupling

TL;DR

This paper investigates adiabatic charge and spin pumping in a two-level quantum dot with spin-orbit coupling, analyzing how various parameters influence pumped currents and demonstrating the potential to generate pure spin currents without charge flow.

Contribution

It provides a detailed theoretical analysis of adiabatic pumping in interacting quantum dots with spin-orbit coupling, including the effects of charging energy and symmetry considerations.

Findings

Pumped charge and spin depend on gate voltages and spin-orbit strength.

Pure spin currents can be generated without charge currents.

The study compares weak and strong charging energy limits.

Abstract

We study adiabatic pumping through a two-level quantum dot with spin-orbit coupling. Using a diagrammatic real-time approach, we calculate both the pumped charge and spin for a periodic variation of the dot's energy levels in the limit of weak tunnel coupling. Thereby, we compare the two limits of vanishing and infinitely large charging energy on the quantum dot. We discuss the dependence of the pumped charge and pumped spin on gate voltages, the symmetry in the tunnel-matrix elements and spin-orbit coupling strength. We identify the possibility to generate pure spin currents in the absence of charge currents.