Probe Quantum Criticality via Finite-Size Dynamical Scaling in Atom Arrays

We experimentally show that the Kibble‑Zurek (KZ) scaling — a universal dynamical signature of phase transitions — can be accurately recovered even when the critical point is smeared out by finite‑size effects or weak symmetry‑breaking perturbations. Using a programmable array of Rydberg atoms that undergoes a Z₂ symmetry‑breaking transition, we demonstrate that by scaling the system size and the symmetry‑breaking field appropriately with the speed of the parameter ramp, the correlation length still follows the characteristic inverse‑power‑law dependence on the ramp speed. This near‑critical scaling protocol avoids the deviations observed in traditional fixed‑size measurements and restores a clear data collapse of correlation functions. Our results establish a practical approach to extract critical exponents in quantum‑simulation platforms where ideal critical points are often inaccessible, thereby strengthening KZ scaling as a robust tool for probing quantum criticality in realistic finite systems.