Quantum emitter in a plasmonic field: An orientation-generalized model

When a quantum emitter (QE) is placed in close proximity to a plasmonic metal nanoparticle within an external optical field, a dipole-dipole coupling arises, resulting in a highly tunable hybrid nanosystem that surpasses the optical manipulation capabilities of the individual components. These hybrid systems enable the exploration and manipulation of optical fields at the intersection between classical and quantum phenomena. Theoretical models of this interaction have typically been limited to the extreme orientations, where the QE and plasmonic dipoles are polarized either along or perpendicular to the interparticle axis, for analytical tractability. In this work, we generalize the semiclassical optical dipole-dipole interaction model for a two-level quantum emitter in a plasmonic field for arbitrary polarization angles. We show that the total field experienced by the quantum emitter at intermediate angles does not necessarily align with the external input field and discuss the implications of varying the polarization angle of the external input field.