August 29, 2006 15:40 WSPC/INSTRUCTION FILE NEW-SZT-ijmpb International Journal of Modern Physics B c  World Scientific Publishing Company MAGNETO-OPTICS OF QUANTUM DOTS IN THE NEAR FIELD CONSTANTINOS SIMSERIDES ∗ Materials Science Department, University of Patras, Panepistimiopolis, Rio, Patras, GR-26504, Greece simserides@upatras.gr, http://www.matersci.upatras.gr ANNA ZORA, GEORGIOS TRIBERIS Physics Department, University of Athens, Panepistimiopolis, Zografos, Athens, GR-15784, Greece azora@phys.uoa.gr, gtriber@phys.uoa.gr Received Day Month Year Revised Day Month Year We examine a quantum dot (QD) illuminated in the near field with subwavelength spatial resolution, while simultaneously it is subjected to a magnetic field of variable orientation and magnitude. The magnetic field orientation can conserve or destroy the zero-magnetic-field (“structural”) symmetry. The asymmetry induced by the magnetic field -except for spe- cific orientations along symmetry axes- can be uncovered in the near-field (NF) but not in the far-field (FF) spectra. We predict that NF magnetoabsorption experiments of realistic spatial resolution could reveal the QD symmetry. This exceptional symmetry- resolving power of the near-field optics, is lost in the far field. Keywords : excitons; absorption; magnetoexcitons; quantum dots; near field. 1. Introduction From the early eighties, the near-field scanning optical microscopy, with applications ranging from semiconductors to biology, has circumvented the so-called “diffraction limit” 1 . All this progress stems from an old idea 2 : the illumination or the light collection is performed in a spot with dimensions smaller than the wavelength, but simultaneously, in order to surpass the “diffraction limit”, the light source or the light detector is placed very close to the sample. The mainly exponentially decaying, evanescent near field instead of the propagating far field is exploited. In this short article we summarize the basic elements of our systematic study of the near-field (NF) magnetoabsorption of single and double quantum dots (QDs) 3 . It is inspired by the experimental 4 and theoretical 5 progress in the field of near-field ∗ See also http://users.uoa.gr/∼csimseri/ 1