Abstract
We report on the microphotoluminescence spectroscopy of InAs/GaAs quantum dots (QDs) doped by a single Mn atom in a magnetic field either longitudinal or perpendicular to the optical axis. In both cases the spectral features of positive trion are found to split into strongly circularly polarized components, an effect very surprising in a perpendicular magnetic field. The field-induced splitting is ascribed to the transverse Zeeman splitting of the neutral acceptor complex issued by the Mn impurity, whereas the circular optical selection rules result from the exchange which acts as a very strong longitudinal magnetic field inhibiting the spin mixing by the transverse field of the QD heavy-hole ground state. A theoretical model of the spin interactions which includes (i) the local strain anisotropy experienced by the acceptor level and (ii) the anisotropic exchange due to the out-of-center Mn position provides a very good agreement with our observations.
- Received 3 September 2009
DOI:https://doi.org/10.1103/PhysRevB.80.165315
©2009 American Physical Society