Quantum surface effects on quantum emitters coupled to surface plasmon polariton

As an ideal platform for exploring strong quantized light-matter interactions, surface plasmon polariton (SPP) has inspired many applications in quantum technologies. Recent experiments discovered that quantum surface effects (QSEs) of the metal, including nonlocal optical response, electron spill-out, and Landau damping, invalidate the classical electromagnetic theory and contribute additional loss sources to the SPP in the nanoscale. This hinders its applications. Going beyond the widely used classical local response approximation, we use the Feibelman $d$-parameter method to investigate the QSE-modified non-Markovian dynamics of quantum emitters (QEs) coupled to a SPP in a planar metal-dielectric nanostructure. A mechanism to overcome the dissipation of the QEs caused by the lossy SPP with the QSEs is discovered. We find that, as long as the QE-SPP bound states are formed, a dissipationless entanglement among the far-separated QEs is created. Compared with the local-response approximate results, the QSEs play a constructive role in establishing such a coherent correlation. The result lays a foundation for understanding the light-matter interactions in absorptive media and paves the way for the application of SPP in quantum network.