  We introduce a three qubit waveguide QED system to mimic the cavity-QED
strong coupling regime of a probe qubit embedded in atom-like mirrors, which
was realized in recent experiments. We then extend this system into the deep
non-Markovian regime and demonstrate the profound role that retardation plays
on the dressed resonances, allowing one to significantly improve the polariton
lifetimes (by many orders of magnitude), tune the resonances, as well as
realize Fano-like resonances and simultaneous coupling to multiple cavity
modes. Exact Green function solutions are presented for the spectral
resonances, and the quantum dynamics are simulated using matrix product states,
where we demonstrate additional control of the cavity-QED system using chiral
probe qubits.
