[1] Univ Evry Val Essonne, INSERM, UEVE U829, F-91025 Evry, France
[2] Univ Stuttgart, Inst Phys 3, D-70550 Stuttgart, Germany
[3] Univ Evry Val Essonne, Nanometr Media Lab, F-91025 Evry, France
[4] ParisTech, Mines Paris, Ctr Mat, F-91000 Evry, France
[5] UTBM, CNRS, UMR 5060, Nanomat Res Grp, F-90010 Belfort, France