Analytic Few Photon Scattering in Waveguide QED for Entanglement Generation
Physical Review A 97, 043850 (2018)
We develop an approach to light-matter coupling in waveguide QED based upon scattering amplitudes evaluated via Dyson series. For optical states containing more than single photons, terms in this series become increasingly complex and we provide a diagrammatic recipe for their evaluation, which is capable of yielding analytic results. Unlike previously reported procedures, our method fully specifies a combined emitter-optical state that permits investigation of matter-matter entanglement generation protocols. We use our expressions to study a scheme for entangling spatially separated two-level systems and find that an entangled two-photon input provides a clear advantage over a separable single photon state.