Bound State in the Continuum and Multiple Atom State Transfer Applications in a Waveguide QED Setup

Bound states in the continuum (BICs) have been extensively exploited to enhance light-matter interactions in metamaterials, yet their emergence and utility in multiatom waveguide platforms remain far less explored. Here we study atom-waveguide-dressed BICs in a one-dimensional coupled-resonator waveguide, where two spatially separated atomic arrays couple to distinct resonators with time-dependent strengths. We show that these BICs host standing-wave photonic components and enable the transfer of unknown atomic quantum states encoded in the single-excitation subspace between the two arrays, with fidelities exceeding 99%. Going beyond traditional cascaded-quantum-network protocols, our scheme leverages BIC-assisted interference to remain robust against both disorder and intrinsic dissipation. Our results establish BICs as long-lived resources for high-fidelity quantum information processing in waveguide-QED architectures.