1. ITMO University, Saint Petersburg 197101, Russia
2. Department of Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden
3. Center for Physical Sciences and Technology, LT-10257 Vilnius, Lithuania
4. University of Texas at Dallas, Richardson, Texas 75080, United States
5. Nonlinear Physics Centre, Australian National University, Canberra, ACT 2601, Australia