  Adiabatic transformation can be approximated as alternating unitary operators
of a Hamiltonian and its parameter derivative as proposed in a gate-based
approach to counterdiabatic driving (van Vreumingen, arXiv:2406.08064). In this
paper, we conduct numerical benchmarking of this alternating unitary method in
a finite-parameter range against adiabatic driving in nonadiabatic timescale.
We find that the alternating unitary method results in broader distribution on
energy eigenstates than that obtained by adiabatic driving, but it has ability
to sample low-energy eigenstates when an energy gap of a given Hamiltonian is
small. It indicates that the alternating unitary method may be able to find
good approximate solutions in quantum annealing applied to hard instances.
