Self Assembled II-VI Magnetic Quantum Dot as a Voltage-Controlled Spin-Filter

TL;DR

This paper reports the first experimental demonstration of a voltage-controlled spin filter using self-assembled II-VI magnetic quantum dots, enabling spin selection without external magnetic fields, advancing spintronics technology.

Contribution

It introduces a novel self-assembled quantum dot device that achieves voltage-controlled spin filtering through local ferromagnetic interactions without external magnetic fields.

Findings

First experimental observation of spin filtering in non-magnetic quantum dots

Demonstrates voltage control of spin polarization

Supports theory of carrier-mediated ferromagnetism in II-VI semiconductors

Abstract

A key element in the emergence of a full spintronics technology is the development of voltage controlled spin filters to selectively inject carriers of desired spin into semiconductors. We previously demonstrated a prototype of such a device using a II-VI dilute-magnetic semiconductor quantum well which, however, still required an external magnetic field to generate the level splitting. Recent theory suggests that spin selection may be achievable in II-VI paramagnetic semiconductors without external magnetic field through local carrier mediated ferromagnetic interactions. We present the first experimental observation of such an effect using non-magnetic CdSe self-assembled quantum dots in a paramagnetic (Zn,Be,Mn)Se barrier.