Spin dynamics of a Mn atom in a semiconductor quantum dot under resonant optical excitation

TL;DR

This paper investigates the spin behavior of a single Mn atom in a quantum dot under resonant laser excitation, revealing a spin trapping mechanism influenced by laser parameters and strain-induced anisotropy.

Contribution

It introduces a model describing how resonant optical excitation and strain anisotropy enable spin population trapping in a Mn atom within a quantum dot.

Findings

Spin population can be trapped in the resonantly excited state under specific conditions.

The trapping mechanism depends on laser detuning and excitation intensity.

Coherent interactions and strain anisotropy control the spin dynamics.

Abstract

We analyze the spin dynamics of an individual magnetic atom (Mn) inserted in a II-VI semiconductor quantum dot under resonant optical excitation. In addition to standard optical pumping expected for a resonant excitation, we show that for particular conditions of laser detuning and excitation intensity, the spin population can be trapped in the state which is resonantly excited. This effect is modeled considering the coherent spin dynamics of the coupled electronic and nuclear spin of the Mn atom optically dressed by a resonant laser field. This spin population trapping mechanism is controlled by the combined effect of the coupling with the laser field and the coherent interaction between the different Mn spin states induced by an anisotropy of the strain in the plane of the quantum dot.