The small-world property (that everyone has a few-step connection to celebrities), for instance, is a prominent result derived in this field. A group of scientists around Professor Cirac, Director at the Max Planck Institute of Quantum Optics (Garching near Munich) and Leader of the Theory Division, has now introduced complex networks in the microscopic, so called, quantum regime (Nature Physics, Advanced Online Publication, DOI:10.1038/NPHYS1665).