Collective spontaneous emission of two atoms side-coupled to a one-dimensional semi-infinite waveguide

Journal article, 2026

We present a theoretical investigation of collective spontaneous emission of two identical two-level atoms side-coupled to a one-dimensional semi-infinite waveguide. The presence of the waveguide boundary naturally induces a feedback interference mechanism. Our results reveal that the collective spontaneous emission rate of the two atoms can be effectively suppressed or enhanced by this interference mechanism, depending on whether the atoms are initially prepared in a symmetric or antisymmetric state. Remarkably, the maximum collective emission rate can reach twice that observed in the case of an infinite waveguide, which arises from Purcell enhancement induced by the waveguide boundary. Further analysis of the two-atom collective dynamics reveals that, under appropriate conditions, an atom-photon bound state can be formed, leading to the confinement of emitted photons within the atom-atom or atom-boundary interspace. These results offer potential applications in quantum information processing based on waveguide quantum electrodynamics.