1. Max Planck Institute for Quantum Optics, D-85748, Garching, Germany
2. Physics Department, Ludwig-Maximilians-Universität Munich, D-85748, Garching, Germany
3. ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
4. ICREA, Passeig Lluís Companys 23, 08010 Barcelona, Spain
5. Institute of Physics of the ASCR, ELI-Beamlines, Na Slovance 2, 182 21, Prague, Czech Republic