Spin-dependent electron transport through a parallel double-quantum-dot structure

TL;DR

This paper theoretically investigates spin-dependent electron transport in a parallel double-quantum-dot system with Rashba spin-orbit coupling, demonstrating spin filtering, separation, and tunable polarization via quantum interference effects.

Contribution

It introduces a novel analysis of spin-dependent transport in a double-quantum-dot structure with local Rashba coupling, revealing controllable spin polarization and separation mechanisms.

Findings

Spin polarization and separation are achievable in the structure.

Electron terminal selection depends on the electron's spin state.

Spin polarizations can be inverted by tuning structural parameters.

Abstract

Electron transport properties in a parallel double-quantum-dot structure with three-terminals are theoretically studied. By introducing a local Rashba spin-orbit coupling, we find that an incident electron from one terminal can select a specific terminal to depart from the quantum dots according to its spin state. As a result, spin polarization and spin separation can be simultaneously realized in this structure. And spin polarizations in different terminals can be inverted by tuning the structure parameters. The underlying quantum interference that gives rise to such a result is analyzed in the language of Feynman paths for the electron transmission.