Open systems theory, starting from the modern formulation of Quantum Mechanics, studies composite, bi- and multipartite systems. Their physics differs in a unique and fundamental way from that of physical systems described by Classical Mechanics and intervenes in questions of principle such as the emergence of the classical world (decoherence), macroscopic irreversibility, the entanglement of quantum phases of matter and radiation, and the concept of quantum measurement.
The effectiveness of new “disruptive” quantum technologies for computation, communication and sensing requires strategies to limit decoherence. In this regard we study in particular the effect of non-Markovian environments, which are the main source of noise in solid-state quantum systems, and the dynamics of open, multistate systems controlled by time-dependent classical fields.