Affiliation: | 1 EME, Dcpartmenta Física Aplicada i Electrònica, Universitat de Barcelona, Diagonal 645-647, 08028, Barcelona, Spain 2 Physics Department, University of Crete, Gr-Heraklion, Crete, Greece 3 Microelectronics Research Group (MRG), IESL, Foundation for Research and Technology of Hellas (FORTH), P.O. Box 1527, Gr-71110 Herakloin, Crete, Greece |