Optical Properties of Manganese-Doped Individual CdTe Quantum Dots
L. Besombesa, Y. Légera, L. Maingaulta, D. Ferranda, C. Bougerola, H. Mariettea and J. Cibertb
a CEA-CNRS group "Nanophysique et Semiconducteurs", Laboratoire de Spectrométrie Physique, CNRS and Université J. Fourier, BP87, 38402 St Martin d'Heres, France
b Laboratoire Louis Néel, CNRS, BP 166X, 38042 Grenoble, France
Full Text PDF
Received: 4 06 2005;
The magnetic state of a single magnetic ion (Mn+2) embedded in an individual quantum dot is optically probed using microspectroscopy. The fine structure of a confined exciton in the exchange field of a single Mn+2 ion (S=5/2) is analyzed in detail. The exciton-Mn+2 exchange interaction shifts the energy of the exciton depending on the Mn+2 spin component and six emission lines are observed at zero magnetic field. The emission spectra of individual quantum dots containing a single magnetic Mn atom differ strongly from dot to dot. The differences are explained by the influence of the system geometry, specifically the in-plane asymmetry of the quantum dot and the position of the Mn atom. Depending on both these parameters, one has different characteristic emission features which either reveal or hide the spin state of the magnetic atom. The observed behavior in both zero field and under magnetic field can be explained quantitatively by the interplay between the exciton-manganese exchange interaction (dependent on the Mn position) and the anisotropic part of the electron-hole exchange interaction (related to the asymmetry of the quantum dot).
DOI: 10.12693/APhysPolA.108.527
PACS numbers:78.67.Hc, 78.55.Et, 75.75.+a