  We provide an exact and complete characterization of the entanglement
dynamics of two qubits coupled to a common structured reservoir at zero
temperature. We derive the conditions to maximize reservoir-induced
entanglement for an initially factorized state of the two-qubit system. In
particular, when the two qubits are placed inside a lossy cavity, we show that
high values of entanglement can be obtained, even in the bad cavity limit, in
the dispersive regime. Finally we show that, under certain conditions, the
entanglement dynamics exhibits quantum beats and we explain their physical
origin in terms of the interference between two different transitions coupling
the dressed states of the system.
