Sprecher
Beschreibung
Persistent revivals recently observed in Rydberg atom arrays have challenged our understanding of thermalisation and attracted much interest to the concept of quantum many-body scarring : the presence of coherent dynamics in otherwise chaotic Hamiltonians. They have since been reported in multiple models, including the kinetically-constrained PXP model realised in Rydberg chains. At the same time, questions of how common scarring is and in what systems it can be observed remain open. In particular, decreasing the spacing between Rydberg atoms to make the constraint act beyond nearest-neighbours seemingly destroys scarring.
In this talk, I will discuss how this breakdown of scarring can be understood through the lens of frustration linked to the constraint. Crucially, this frustration can be lifted by entanglement, making it possible to witness coherent oscillations for an arbitrary constraint range. However, in contrast to the PXP model, their observation requires launching dynamics from weakly entangled initial states rather than from a product state. This key insight allows us to demonstrate that scarring exists in a much broader family of experimentally-realisable models that includes and generalises PXP to longer-range constraints and states with different periodicity. Our approach can also be used in higher dimensions where frustration is more ubiquitous, revealing a plethora of new scarred trajectories.
