  Dicke superradiance is an example of emergence of macroscopic quantum
coherence via correlated dissipation. Starting from an initially incoherent
state, a collection of excited atoms synchronizes as they decay, generating a
macroscopic dipole moment and emitting a short and intense pulse of light.
While well understood in cavities, superradiance remains an open problem in
extended systems due to the exponential growth of complexity with atom number.
Here we show that Dicke superradiance is a universal phenomenon in ordered
arrays. We present a theoretical framework -- which circumvents the exponential
complexity of the problem -- that allows us to predict the critical distance
beyond which Dicke superradiance disappears. This critical distance is highly
dependent on the dimensionality and atom number. Our predictions can be tested
in state of the art experiments with arrays of neutral atoms, molecules, and
solid-state emitters and pave the way towards understanding the role of
many-body decay in quantum simulation, metrology, and lasing.
