1. Institut d'Electronique, de Microélectronique et de Nanotechnologies (IEMN), CNRS, UMR 8520, Département ISEN, 41 bd Vauban, 59046 Lille Cedex, France
2. Key Laboratory of Advanced Display and System Application, Shanghai University, 149 Yanchang Road, Shanghai 200072, People's Republic of China
3. CNRS-Laboratoire de Photonique et de Nanostructures (LPN), Route de Nozay, 91460 Marcoussis, France
4. CNRS-Laboratoire d'Analyse et d'Architecture des Systèmes (LAAS), Univ. de Toulouse, 7 Avenue du Colonel Roche, F-31400 Toulouse, France
5. Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
6. Peter Grünberg Institut, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany