1. Department of Theoretical Physics, Institute of Physics, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary
2. Nokia Bell Labs
3. Óbuda University
4. Wigner Research Centre for Physics, H-1525 Budapest, P.O.Box 49, Hungary
5. Eötvös University, Budapest, Hungary
6. MTA-BME Quantum Dynamics and Correlations Research Group, Műegyetem rkp. 3., H-1111 Budapest, Hungary