  Physical systems in the time domain may exhibit analogous phenomena in real
space, such as time crystals, time-domain Fresnel lenses, and modulational
interference in a qubit. Here we report the experimental realization of
time-domain grating using a superconducting qutrit in periodically modulated
probe and control fields via two schemes: Simultaneous modulation and
complementary modulation. Both experimental and numerical results exhibit
modulated Autler-Townes (AT) and modulation-induced diffraction (MID) effects.
Theoretical results also confirm that the peak positions of the interference
fringes of AT and MID effects are determined by the usual two-level relative
phases, while the observed diffraction fringes, appearing only in the
complementary modulation, are however related to the three-level relative
phase. Further analysis indicates that such a single-atom time-domain
diffraction originates from the correlation effect between the two time-domain
gratings. Moreover, we find that the widths of the diffraction fringes are
independent of the control-field power. Our results shed light on the
experimental exploration of quantum coherence for modulated multi-level systems
and may find promising applications in fast all-microwave switches and
quantum-gate operations in the strong-driving regime.
