RAVE · UnRAVElling the dynamics of many-body open systems: Collective dynamics of quantum trajectories

With the flourishing of quantum information processing, the study of open quantum system dynamics has become of paramount importance for the ultimate success of quantum technologies. The phenomenology becomes increasingly rich when decoherence and dissipation arise in quantum systems with many degrees of freedom, leading to a flurry of different phases of matter. RAVE is devoted to the study of collective phenomena in synthetic, many-body open quantum systems through investigation of the dynamics of quantum trajectories. Following the dynamics at the level of its trajectories will capture features that are washed out by looking at averaged observables, i.e. in the density matrix. RAVE will show that there are collective phenomena visible only in the dynamics of single trajectories, and propose experimental schemes to observe them. This will lead to a new classification of phases in quantum many-body open systems and help clarify the relations between entanglement, correlations and non-equilibrium thermodynamics. In those cases where the steady-state phase breaks time-translational invariance, RAVE will contribute to unify apparently different concepts such as synchronisation and time-crystals. The statistics associated with the behaviour of quantum jumps in many-body systems is also important for characterizing the quality and performance of quantum information processing protocols. To address the key questions posed by the project, RAVE will develop a promising new methodology based on replicas and use it to design open system quantum simulators able to provide information at the level of single trajectories. RAVE is a highly interdisciplinary programme which will have significant impact in the fields of condensed matter, statistical physics, quantum information and stochastic thermodynamics.