Single-photon scattering by a nanofiber-coupled atomic chain: beyond independent radiation

We study single-photon scattering by a nanofiber-coupled atomic chain, comparing a full microscopic model with an independent-radiation approximation. We show that nearly equal transmission probabilities can coexist with substantially different transmitted temporal modes, even after adjusting their relative delay. For a reference chain, a decomposition into collective atomic resonances relates this discrepancy mainly to spectral-phase changes caused by the omitted interatomic couplings. Parameter scans delimit this phase-dominated regime, and controlled comparisons separate the effects of coherent exchange and collective decay.