Optical orientation of a single Mn spin in a quantum dot: Role of carrier spin relaxation

TL;DR

This paper explains the optical orientation of a single Mn spin in a quantum dot by showing that carrier spin relaxation, combined with state mixing due to exchange interaction, accounts for the observed Mn spin dynamics.

Contribution

It demonstrates that carrier spin relaxation alone can explain the Mn spin orientation times, considering the exciton-Mn state mixing caused by sp-d exchange interaction.

Findings

Carrier spin relaxation explains Mn optical orientation times.

State mixing due to exchange interaction influences spin dynamics.

Observed timescales are consistent with relaxation processes.

Abstract

In order to explain the recently observed phenomenon of optical orientation of a single Mn spin residing inside a quantum dot, a process of Mn spin relaxation with characteristic timescale of tens of nanoseconds had been invoked. We show that after taking into account the mixing of states of the exciton and the Mn spin (due to the sp-d exchange interaction), the observed Mn optical orientation time can be explained by invoking only the processes of carrier spin relaxation.