Affiliation: | a I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, D-20355 Hamburg, Germany b Theoretical Physics and Applied Mathematic Department, Urals State Technical University, 620002, Mira street 19, Yekaterinburg, Russia c Institute of Metal Physics, Russian Academy of Sciences, 620041 Yekaterinburg GSP-170, Russia |