Ticking-clock performance enhanced by nonclassical temporal correlations

We investigate the role of nonclassical temporal correlations in enhancing performance ticking clocks a discrete-time scenario. show that problem optimal models for is related to violation Leggett-Garg-type inequalities formulated terms of, possibly invasive, sequential measurements, but on system with bounded memory capacity. Ticking inspire derivation family showing gap between classical and quantum correlations, despite involving no input. ticking-clock achieving accuracy beyond bound are also those violating finite sequences we their continuous-time limit. Interestingly, clock scenario do not have well-defined limit, feature absent models.