Formation of pure two-electron triplet states in weakly coupled quantum dots attached to ferromagnetic leads

TL;DR

This paper investigates spin-dependent transport in weakly coupled quantum dots with ferromagnetic leads, revealing the formation of pure triplet states and new spin blockade regimes due to lead polarization effects.

Contribution

It demonstrates the formation of pure two-electron triplet states in quantum dots attached to ferromagnetic leads, highlighting novel spin blockade phenomena.

Findings

Pure triplet states form in specific lead configurations.

Additional spin blockade regimes emerge with opposite spin occupations.

Spin-dependent transport is significantly affected by lead polarization.

Abstract

Weakly coupled quantum dots in the Pauli spin blockade regime are considered with respect to spin-dependent transport. By attaching one half-metallic and one non-magnetic lead, the Pauli spin blockade if formed by a pure triplet state with spin moment $S_z=1$ or -1. Furthermore, additional spin blockade regimes emerge because of full occupation in states with opposite spin to that of the half-metallic lead.