  Quantum computers promise a qualitative speedup in solving a broad spectrum
of real-life optimization problems. The latter can be mapped onto the task of
finding low-energy states of spin glasses, which is known to be exceedingly
difficult. Using D-Wave's 5000-qubit quantum processor, we demonstrate that a
recently proposed iterative cyclic quantum annealing algorithm[1] can find deep
low-energy states in record time. We also find intricate structures in a
low-energy landscape of spin glasses, such as a power-law distribution of
connected clusters with a small surface energy. These observations offer
guidance for further improvement of the optimization algorithms.
