The single ion of Vanadium in an individual Quantum Dot

We present the basic properties of a new physical system: an individual V2+ ion embedded into an individual quantum dot. The system is realized utilizing molecular beam epitaxy and it is observed using a low-temperature polarization-resolved magneto-photoluminescence. The nature of the system is confirmed by observation of the excitonic lines split due to the interactions of a vanadium ion with carriers confined in a CdTe/ZnTe quantum dot. Observed data are explained by the numerical modeling which includes s,p-d exchange interaction, Zeeman splitting of the exciton and the ion, diamagnetic shift, and the presence of shear strain within the quantum dot. The fundamental state of vanadium exhibits a spin 1/2 making this system a textbook localized qubit.