Quantum Plasmonic Dynamics Modeled via a Modified Langevin Noise Formalism: Numerical Studies of Single-Photon Emission and Two-Photon Interference.

Recent studies have established and rigorously validated a modified Langevin noise formalism that enables macroscopic-QED-based quantization of electromagnetic fields in open and dissipative environments. Building on this foundation, a multimode Jaynes-Cummings framework has been developed and verified, providing an accurate description of atom-field interactions in lossy and radiative systems. In this work, we explore the potential of this formalism for nanophotonic applications by modeling representative quantum-plasmonic dynamics. In particular, we present detailed numerical examples for (i) two-photon interference mediated by a quantum plasmonic beam splitter, and (ii) non-Markovian dynamics of an atom located in plasmonic antennas and corresponding directional control of out-coupled single-photon fields. These results illustrate how the proposed modeling approach can provide quantitative insight into the behavior of plasmonic single-photon sources and beam-splitting structures.