Near-Field Magneto-Photoluminescence of Singe Self-Organized Quantum Dots.

We present results obtained using low temperature near-field scanning optical microscopy for the measurements of Zeeman splitting and the diamagnetic shift of single self-organized InAs/AlAs, InAs/GaAs and InP/GaInP quantum dots. The measurements allow us to relate the bimodal size distribution of InAs dots with variations in In content. For single InP QDs we observed a strong circular polarization at zero magnetic field accompanied with a negative energy shift, suggesting that strong internal magnetic fields exist in these QDs.