1. Departamento de Física
da Materia Condensada, Facultade de Física, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela,
Spain
2. LITEN, CEA-Grenoble, 17 rue des Martyrs, BP166, 38054 Grenoble, France
3. Department of Theoretical Chemistry & Biology, School of Biotechnology, Royal Institute of Technology, SE-106 91 Stockholm, Sweden
4. Institute for Lasers, Photonics
and Biophotonics, Department of Chemistry, State University of New York, Buffalo, New York 14260-3000, United States