[1] Free Univ Berlin, Dahlem Ctr Complex Quantum Syst, D-14195 Berlin, Germany
[2] Free Univ Berlin, Fachbereich Phys, D-14195 Berlin, Germany
[3] Budapest Univ Technol & Econ, Dept Theoret Phys, Erot Quantum Phases Momentum Res Grp, Budafoki Ut 8, H-1111 Budapest, Hungary
[4] Budapest Univ Technol & Econ, Inst Phys, MTA BME Quantum Correlat Grp, Budafoki Ut 8, H-1111 Budapest, Hungary
[5] Univ Cologne, Inst Theoret Phys, Zulpicher Str 77a, D-50937 Cologne, Germany