Spin polarization in open quantum dots

TL;DR

This paper studies spin-polarized electron transport in open quantum dots using LSDA, revealing density-dependent spin polarization effects and questioning simplified modeling approaches.

Contribution

It introduces a detailed LSDA-based method for analyzing spin transport in quantum dots, highlighting the limitations of simplified models.

Findings

Spin polarization occurs at low electron densities.

Spin polarization diminishes as electron density increases.

Simplified models may not reliably predict spin phenomena.

Abstract

We investigate coherent transport through open lateral quantum dots using recursive Green's function technique, incorporating exchange-correlation effects within local spin-density approximation (LSDA). At low electron densities the current is spin-polarized and electron density in the dot shows a strong spin polarization. As the electron density increases the spin polarization in the dot gradually diminishes. These findings are consistent with available experimental observations. Results of our LSDA-based modeling indicate that utilization of the simplified approaches that use phenomenological parameters and/or model Hamiltonians might not be always reliable for theoretical predictions as well as interpretations of the experiments.