New rigorous insights into scars in PXP-type systems

Kinetically constrained PXP-type models representing Rydberg atom chains in the strong Rydberg blockade regime (parametrized by the blockade radius) are paradigmatic for studying non-ergodic phenomena in non-integrable quantum systems. We discuss new rigorous results which may provide a new perspective on the thermalization phenomenology and mechanisms of scars in the still-mysterious one-dimensional PXP-type systems. In particular, we analyze the unusual periodic revivals of the charge density wave (CDW) state observed in quench experiments and discuss the implications for better understanding this dynamics in the thermodynamic limit. This has proven to be a difficult problem, as no closed-form expressions are available for the primary members of scar towers believed to play a major role in the revivals due to their high overlap with the CDW state. From our results, we also deduce several new examples of scars possible in various PXP-type systems.