1. Universidad de Salamanca,Applied Physics Department and USAL-NANOLAB,Salamanca,Spain
2. Univ. Lille, CNRS, Univ. Polytechnique Hauts-de-France, UMR 8520 – IEMN,Lille,France,F-59000
3. Nanyang Technological University,CINTRA, Temasek Laboratories,Singapore,637553