[1] Ecole Cent Paris, Lab Struct Proprietes & Modelisat Solides, UMR CNRS, F-92295 Chatenay Malabry, France
[2] Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia
[3] Augusta Tech Coll, Dept Phys, Augusta, GA 30906 USA
[4] Univ Arkansas, Inst Nanosci & Engn, Fayetteville, AR 72701 USA
[5] Univ Arkansas, Dept Phys, Fayetteville, AR 72701 USA