[1] Bilkent Univ, Dept Phys, TR-06800 Ankara, Turkey
[2] CNRS, Inst Rech Interdisciplinaire, USR3078, F-59658 Villeneuve Dascq, France
[3] Univ Lille 1, F-59658 Villeneuve Dascq, France
[4] Aalto Univ, Sch Sci, Dept Appl Phys, FI-00076 Espoo, Finland
[5] Aalto Univ, Sch Sci, COMP Ctr Excellence, FI-00076 Espoo, Finland
[6] Brown Univ, Dept Phys, Providence, RI 02912 USA