We studied the spin dynamics of a Cr atom incorporated in a II-VI semiconductor quantum dot using photon correlation techniques. We used recently developed singly Cr-doped CdTe/ZnTe quantum dots (A. Lafuente-Sampietro {\it et al.}, [1]) to access the spin of an individual magnetic atom. Auto-correlation of the photons emitted by the quantum dot under continuous wave optical excitation reveals fluctuations of the localized spin with a timescale in the 10 ns range. Cross-correlation gives quantitative transfer time between Cr spin states. A calculation of the time dependence of the spin levels population in Cr-doped quantum dots shows that the observed spin dynamics is controlled by the exciton-Cr interaction. These measurements also provide a lower bound in the 20 ns range for the intrinsic Cr spin relaxation time.
@article{arxiv.1606.05476,
title = {Spin dynamics of an individual Cr atom in a semiconductor quantum dot under optical excitation},
author = {A. Lafuente-Sampietro and H. Utsumi and H. Boukari and S. Kuroda and L. Besombes},
journal= {arXiv preprint arXiv:1606.05476},
year = {2016}
}