Romaner, Lorenz; Georgia Inst Technol, Atlanta, GA 30332 USA
Hofmann, Oliver T.; Graz Univ Technol, Inst Solid State Phys, A-8010 Graz, Austria
Zojer, Egbert; Graz Univ Technol, Inst Solid State Phys, A-8010 Graz, Austria
Ambrosch-Draxl, Claudia; Univ Leoben, Dept Mat Phys, A-8700 Leoben, Austria
Scheffler, Matthias; Max Planck Soc, Fritz Haber Inst, Berlin, Germany