Optical Spectroscopy on Single Semimagnetic Quantum Dots ? Probing the Interaction between an Exciton and Its Magnetic Environment

Abstract

Single diluted magnetic semiconductor (DMS) quantum dots are studied by means of photoluminescence spectroscopy and magnetoluminescence. The sp–d exchange interaction between a single electron–hole pair and roughly 100 Mn spins within the dot is demonstrated to result in (i) a significant enhancement (more than one order of magnitude) of the emission linewidth and (ii) a strongly modified magnetic field dependence of the polarization degree in a single DMS quantum dot as compared to a non-magnetic reference sample.