1. Department of Theoretical Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary
2. MTA-BME Quantum Dynamics and Correlations Research Group, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary
3. Department of Physics and Materials Science, University of Luxembourg, L-1511 Luxembourg, Luxembourg
4. Universitö de Lorraine, CNRS, LPCT, F-54000 Nancy, France
5. Leibniz Institute for Solid State and Materials Research, IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany
6. Würzburg-Dresden Cluster of Excellence ct.qmat, 01062 Dresden, Germany
7. HUN-REN Wigner Research Centre for Physics, H-1525 Budapest, P.O. Box 49, Hungary