Electrical Spin Pumping of Quantum Dots at Room Temperature

TL;DR

This paper demonstrates electrical control of spin polarization in quantum dots at room temperature using an Fe contact, achieving a stable 5% electron spin polarization, indicating potential for practical spintronic devices.

Contribution

It introduces a method for electrical spin injection into quantum dots at room temperature, showing stable spin polarization unaffected by temperature variations.

Findings

Achieved 5% electron spin polarization in InAs QDs at 300 K.

Spin polarization remains stable across temperature changes.

Electrical injection from Fe Schottky contact effectively controls spin states.

Abstract

We report electrical control of the spin polarization of InAs/GaAs self-assembled quantum dots (QDs) at room temperature. This is achieved by electrical injection of spin-polarized electrons from an Fe Schottky contact. The circular polarization of the QD electroluminescence shows that a 5% electron spin polarization is obtained in the InAs QDs at 300 K, which is remarkably insensitive to temperature. This is attributed to suppression of the spin relaxation mechanisms in the QDs due to reduced dimensionality. These results demonstrate that practical regimes of spin-based operation are clearly attainable in solid state semiconductor devices.