Exact quantum scars of frustrated hardcore bosons for cross-platform realizations

Quantum many-body scars are nonthermal states exhibiting persistent revivals in an otherwise ergodic, nonintegrable quantum system. Existing examples of exact quantum scars, however, have not yet been amenable to direct experimental demonstration. Here we show that a minimal model of hardcore bosons hopping on a π-flux ladder is sufficient to give rise to an exact scar due to kinetic frustration. The simplicity of this model makes it suitable for multiple existing quantum simulation platforms, which we illustrate with proposals for cold atom Bose-Hubbard simulators and polar molecule or Rydberg atom tweezer arrays. In these platforms, the scar lifetime can be extended by tuning experimentally accessible parameters, like the Hubbard interaction or a Floquet drive. Finally, we introduce a practical heuristic based on the energy distribution of eigenstates for systematically predicting and optimizing quantum many-body scar lifetimes. Their cross-platform realizability and long lifetimes make them well-suited for benchmarking coherence and exploring nonergodic dynamics in current and near-term quantum devices.