Affiliation: | 1. Department of Condensed Matter Physics and Materials Science Brookhaven National Laboratory Upton NY 11973 (USA);2. Ioffe Physical Technical Institute 26 Polytechnical Street St. Petersburg 194021 (Russia);3. Department of Mathematics San Jose State University San Jose, California 95192 (USA);4. Department of Physics University of Belgrade Belgrade 11000 (Serbia) |