1. Quantum Technology Lab, Dipartimento di Fisica, Università degli Studi di Milano, I-20133 Milano, Italy
2. Institute of Physics, Jagiellonian University, 30-348 Kraków, Poland; Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, 80-233 Gdańsk, Poland; and Departamento de Física, Facultad de Ciencias Básicas, Universidad de Antofagasta, Casilla 170, Antofagasta, Chile
3. Institute of Physics, Jagiellonian University, 30-348 Kraków, Poland and Center for Theoretical Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland