  In this paper, we investigate the single-photon scattering and bound states
in a one-dimensional coupled-resonator waveguide which couples to a single
artificial giant atom with two or more coupling points. When the atom couples
to the waveguide via two resonators, the single-photon reflection rate is
characterized by either Breit-Wigner or Fano line shapes. When the atom couples
to the waveguide via multiple resonators, we numerically show how the
destructive interference effect leads to a complete single-photon reflection.
We also find a phase transition phenomena for the multi-resonator coupling
case, which reveals that the upper bound state only exists when the
atom-waveguide coupling strength is above a critical value.
