  Driven by the need to develop efficient atom-photon interfaces, recent
efforts have proposed replacing cavities by large arrays of cold atoms that can
support subradiant or superradiant collective states. In practice, subradiant
states are decoupled from radiation, which constitutes a hurdle to most
applications. In this work, we study theoretically a protocol that bypasses
this limit using a one dimensional (1D) chain composed of N three-level atoms
in a V-shaped configuration. Throughout the protocol, the chain behaves as a
time-varying metamaterial: enabling absorption, storage and on-demand emission
in a spectrally and spatially controlled mode. Taking into account the quantum
nature of atoms, we establish the boundary between the linear regime and the
nonlinear regime. In the nonlinear regime, we demonstrate that doubly-excited
states can be coherently transferred from superradiant to subradiant states,
opening the way to the optical characterization of their entanglement.
