1. Department of Physics, Nano-magnetism Research Center, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
2. Instituto de Engenharia de Sistemas e Computadores – Microsistemas e Nanotecnologias (INESC MN), 1000-029 Lisbon, Portugal
3. Departamento de Física, Instituto Superior Tecnico (IST), Universidade de Lisboa, 1040-001 Lisbon, Portugal