The research activity of these theoretical groups focuses on the analytical and numerical investigation of single-particle and many-body quantum systems where quantum features as entanglement, coherence, noise and interference may lead to unexpected and surprising effects in their performance to achieve a given task. These studies have fundamental and applied implications in several fields, ranging from quantum information science to quantum sensing, from quantum communication to quantum computation, from quantum simulation to quantum biology and quantum machine learning. Our theoretical predictions and optimally designed quantum algorithms can be experimentally tested on quantum optics and condensed-​matter physics platforms as single photons, clouds of ultracold atoms, trapped ions, and atomic/photonic interfaces, thanks also to local and international experimental collaborations of these theoretical groups.