  A bang-bang (BB) algorithm prepares the ground state of a two-dimensional
(2D) quantum many-body Hamiltonian $H=H_1+H_2$ by evolving an initial product
state alternating between $H_1$ and $H_2$. We use the neighborhood tensor
update to simulate the BB evolution with an infinite pair-entangled projected
state (iPEPS). The alternating sequence is optimized with the final energy as a
cost function. The energy is calculated with the tangent space methods for the
sake of their stability.
  The method is benchmarked in the 2D transverse field quantum Ising model near
its quantum critical point against a ground state obtained by variational
optimization of the iPEPS. The optimal BB sequence differs non-perturbatively
from a sequence simulating quantum annealing or adiabatic preparation (AP) of
the ground state. The optimal BB energy converges with the number of bangs much
faster than the optimal AP energy.
