Spin current generation and detection by a double quantum dot structure

TL;DR

This paper proposes a double quantum dot device functioning as a spin valve, capable of generating highly spin-polarized currents under specific conditions, with analysis of factors affecting its efficiency and experimental feasibility.

Contribution

It introduces a novel quantum dot-based spin valve design and provides an analytical framework for understanding its spin-polarization capabilities.

Findings

Electric current can become nearly fully spin-polarized under certain parameters.

Coupling asymmetry and temperature influence device efficiency.

Predictions for experimental realization are provided.

Abstract

We propose a device acting as a spin valve which is based on a double quantum dot structure with parallel topology. Using the exact analytical solution for the noninteracting case we argue that, at a certain constellation of system parameters and externally applied fields, the electric current through the constriction can become almost fully spin-polarized. We discuss the influence of the coupling asymmetry, finite temperatures and interactions on the efficiency of the device and make predictions for the experimental realization of the effect.