  We investigate the transition of a two-level atom as the Unruh-Dewitt
detector accelerated in the electromagnetic field in this paper. The
enhancement of the transition probability is found for different field states
under the conditions that the anti-Unruh effect appears. In particular, the
enhancement is the most prominent when the field state takes the squeezed
state. We also construct a new atomic trajectory to realize the effect of
acceleration-induced transparency. Based on this, we show that the anti-Unruh
effect still exists even at the specific atomic energy difference where
acceleration-induced transparency happens.
