1. Theoretical
Physics Department, Faculty of Physics, Vilnius University, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania
2. Center for Physical Sciences and Technology, A. Gostauto 11, LT-01108 Vilnius, Lithuania
3. Institut
de Biologie et de Technologie de Saclay, CEA, UMR 8221 CNRS, University Paris Sud, CEA Saclay, 91191 Gif sur Yvette, Paris, France