Quantum quenches from the critical point: theory and experimental validation in a trapped-ion quantum simulator

We investigate quantum quenches starting from a critical point and experimentally probe the associated defect statistics using a trapped-ion quantum simulator of the transverse-field Ising model. The cumulants of the defect number distribution exhibit universal scaling with quench depth, featuring Gaussian behavior at leading order and systematic subleading corrections. Our results provide direct experimental validation of existing theoretical predictions and extend them to the full statistical characterization of defects. Beyond this, they establish, to the best of our knowledge, the first controlled experimental benchmark for fast-quench defect statistics near quantum criticality, providing a solid foundation for future studies of more complex, non-integrable quantum systems, thereby guiding both theoretical and experimental investigations of nonequilibrium quantum critical phenomena.