Detection of spin bias in four-terminal quantum-dot ring

TL;DR

This paper proposes a practical electrical method to detect spin bias in a four-quantum-dot ring by observing charge currents influenced by spin-dependent quantum interference caused by Rashba spin-orbit interaction.

Contribution

It introduces a novel scheme utilizing Rashba spin-orbit interaction to electrically detect spin bias through charge current measurements in quantum-dot rings.

Findings

Charge currents depend on spin bias magnitude and polarization.

Spin-dependent quantum interference causes observable charge currents.

Method offers a practical way to detect spin bias electrically.

Abstract

In this work, we show that in a four-quantum-dot ring, via introducing a local Rashba spin-orbit interaction the spin bias in the transverse terminals can be detected by observing the charge currents in the longitudinal probes. It is found that due to the Rashba interaction, the quantum interference in this system becomes spin-dependent and the opposite-spin currents induced by the spin bias can present different magnitudes, so charge currents emerge. Besides, the charge currents rely on both the magnitude and spin polarization direction of the spin bias. It is believed that this method provides an electrical but practical scheme to detect the spin bias (or the spin current).