Optically probing the fine structure of a single Mn atom in an InAs quantum dot

TL;DR

This study uses optical spectroscopy to investigate the fine structure of a single Mn atom in an InAs quantum dot, revealing its spin state and magnetic interactions with carriers under a magnetic field.

Contribution

It provides new insights into the spin properties and magnetic interactions of a single Mn impurity in a quantum dot, highlighting the ferromagnetic coupling with holes.

Findings

Mn impurity is a neutral acceptor state A^0 with spin J=1

Ferromagnetic interaction with holes, negligible with electrons

Effective coupling constant of a few hundreds of micro-eV

Abstract

We report on the optical spectroscopy of a single InAs/GaAs quantum dot (QD) doped with a single Mn atom in a longitudinal magnetic field of a few Tesla. Our findings show that the Mn impurity is a neutral acceptor state A^0 whose effective spin J=1 is significantly perturbed by the QD potential and its associated strain field. The spin interaction with photo-carriers injected in the quantum dot is shown to be ferromagnetic for holes, with an effective coupling constant of a few hundreds of micro-eV, but vanishingly small for electrons.