1. Institute for Theoretical PhysicsJohannes Kepler University Linz Altenberger Straße 69 A-4040 Linz Austria
2. Max Planck Institute of Microstructure Physics Weinberg 2 D-06120 Halle (Saale) Germany
3. Institute of PhysicsMartin Luther University Halle-Wittenberg Von-Seckendorff-Platz 1 D-06120 Halle (Saale) Germany
4. G. V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine 36 Academician Vernadsky Boulevard UA-03142 Kyiv Ukraine
5. NorditaKTH Royal Institute of TechnologyStockholm University Roslagstullsbacken 23 S-10691 Stockholm Sweden