Tailoring quantum radiation with giant atoms for quantum metrology

Giant atoms—quantum emitters coupled to a continuum at multiple, spatially separated points—offer a powerful platform for nonlocal light–matter interactions. We study the radiation emitted by coherently driven giant atoms in a Markovian waveguide environment, focusing on how the spectral and statistical properties of the transmitted field can be tailored by tuning intrinsic parameters such as coupling-point positions, accumulated phase, and network topology. We also explore the metrological potential of this radiation, assessing quantum sensing strategies based on photon-counting and homodyne detection to infer system parameters. Our results illustrate how the nonlocal nature of giant atoms enables tunable radiation and enhanced sensitivity, opening new directions for engineered quantum optics and precision measurements.