V. Zlatić,1,2 R. Monnier,3 and J. K. Freericks4 1Institute of Physics, Bijenička c. 46, 10001 Zagreb, Croatia 2International School for Advanced Studies (SISSA), Via Beirut 2-4, I-34014 Trieste, Italy 3ETH Hönggerberg, Laboratorium für Festkörperphysik, 8093 Zürich, Switzerland 4Department of Physics, Georgetown University, Washington, D.C. 20057, USA Received 7 April 2008; revised manuscript r...