The role of coherence in Quantum Reservoir Computing

The study of quantum systems from the perspective of Reservoir Computing is a promising angle that has been increasingly raising interest in the past few years, since our current technology allowed for the experimental realisation of such systems. This work explores the
relation between the coherence present in the quantum reservoir and its ability to process information in the context of the resource theory of coherence. For this we take the transverse-field Ising model as our reservoir, which we study in its different dynamical regimes as a
function of the intensity of the magnetic field and the disorder present within. We are able to link the operational regimes of the reservoir with higher values of the coherence, and relate the dynamics of each phase to its processing capacity. In addition, we perform an analysis of the robustness of these reservoirs to phase and bit flip noise, which shows that the latter is more destructive than the former for the system’s ability to process information. Our results also establish a link between quantum correlations and high-order degrees of nonlinear processing capacity.