  We propose a modified quantum annealing protocol, i. e., pulsed quantum
annealing} (PQA), in order to increase the success probability by a pulse
application during the quantum annealing process. It is well known that the
success probability of the conventional quantum annealing is reduced due to the
Landau-Zener transitions. By applying a pulse to the system, we modulate the
success probability and increase it, compared to the conventional quantum
annealing, by optimizing the pulse parameters. We demonstrate our findings for
a single qubit both numerically and analytically. The analytical model is based
on the tranfer matrix approach and it is in good agreement with the full
numerical results. We also investigate the PQA protocol for multi-qubit cases
$i. e.,$ random spin-glass instances, and we present an overall increase of the
success probability over the conventional quantum annealing, by optimizing the
pulse parameters. Our results indicate that PQA can be used to design future
high-performance quantum annealing machines, especially for hard instances that
the conventional QA protocol behaves poorly.
