  We study the decay dynamics of a two-level giant atom that is coupled to a
waveguide with time-dependent coupling strengths. In the non-Markovian regime
where the retardation effect cannot be ignored, we show that the dynamics of
the atom depends on the atom-waveguide coupling strengths at an earlier time.
This allows one to tailor the decay dynamics of the giant atom and even realize
a stationary population revival with appropriate coupling modulations.
Moreover, we demonstrate the possibility of simulating the quantum Zeno and
quantum anti-Zeno effects in the giant-atom model with periodic coupling
quenches. These results have potential applications in quantum information
processing and quantum network engineering.
