Optical spin orientation of a single manganese atom in a quantum dot

TL;DR

This study demonstrates high spin polarization of a single manganese atom in a quantum dot through optical excitation, revealing control over magnetic moments via photon helicity and strain-induced anisotropy.

Contribution

It introduces a method to achieve and control spin polarization of a single Mn atom in a quantum dot at zero magnetic field using optical techniques.

Findings

High spin polarization achieved with quasi-resonant excitation

Spin lifetime influenced by strain-induced magnetic anisotropy

Magnetic moment orientation controlled by photon helicity

Abstract

A hight degree of spin polarization is achieved for a Mn atom localized in a semiconductor quantum dot using quasi-resonant optical excitation at zero magnetic field. Optically created spin polarized carriers generate an energy splitting of the Mn spin and enable magnetic moment orientation controlled by the photon helicity and energy. The dynamics and the magnetic field dependence of the optical pumping mechanism shows that the spin lifetime of an isolated Mn atom at zero magnetic field is controlled by a magnetic anisotropy induced by the built-in strain in the quantum dots.