  The ability to efficiently prepare ground states of quantum Hamiltonians via
adiabatic protocols is typically limited by the smallest energy gap encountered
during the quantum evolution. This presents a key obstacle for quantum
simulation and realizations of adiabatic quantum algorithms in large systems,
particularly when the adiabatic gap vanishes exponentially with system size.
Using QuEra's Aquila programmable quantum simulator based on Rydberg atom
arrays, we experimentally demonstrate a method to circumvent such limitations.
Specifically, we develop and test a "sweep-quench-sweep" quantum algorithm in
which the incorporation of a quench step serves as a remedy to the diverging
adiabatic timescale. These quenches introduce a macroscopic reconfiguration
between states separated by an extensively large Hamming distance, akin to
quantum many-body scars. Our experiments show that this approach significantly
outperforms the adiabatic algorithm, illustrating that such quantum quench
algorithms can provide a shortcut to adiabaticity for large-scale many-body
quantum systems.
