1. Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193 Barcelona, Spain
2. Laboratory
of Electron Nanoscopies (LENS)−MIND-IN2UB, Department d’Electronica, Universitat de Barcelona, carrer Martí i Franquès 1, 08028 Barcelona, Spain
3. ICREA, Pg. Llus Companys 23, 08010 Barcelona, Spain
4. Vall d’Hebron Institut de Recerca (VHIR), 08035 Barcelona, Spain