Giant atoms in a two-dimensional structured environment — protection from decoherence

Giant atoms are a new paradigm of quantum emitters that break the dipole approximation by coupling to light at multiple discrete points. Among their many promising properties, giant atoms have the ability to interact via a one-dimensional waveguide without decohering. Here, we study how giant atoms behave when coupled to a two-dimensional square lattice of coupled cavities. This particular environment has an energy spectrum characterized by finite bands and band gaps, which affect atomic dynamics beyond the Markovian regime. In this talk, we will show how giant atoms can avoid decoherence (through subradiance, decoherence-free interaction, and the overlap of bound states), and how their dynamics compare to that of small atoms and continuous waveguides. The results shown here may find applications in quantum simulation and quantum information processing.