• DOI:10.1088/1361-6528/acb5a8
• Corpus ID: 251402538

Degenerate parametric down-conversion facilitated by exciton-plasmon polariton states in nonlinear plasmonic cavity.

@article{Piryatinski2022DegeneratePD,
  title={Degenerate parametric down-conversion facilitated by exciton-plasmon polariton states in nonlinear plasmonic cavity.},
  author={Andrei Piryatinski and Maxim Sukharev},
  journal={Nanotechnology},
  year={2022}
}

• A. Piryatinski, M. Sukharev
• Published 8 August 2022
• Physics
• Nanotechnology

We study the effect of degenerate parametric down-conversion (DPDC) in an ensemble of two-level quantum emitters (QEs) coupled via near-field interactions to a single surface plasmon (SP) mode of a nonlinear plasmonic cavity. For this purpose, we develop a quantum driven-dissipative model capturing non-equilibrium dynamics of the system in which incoherently pumped QEs have transition frequency tuned near the second-harmonic response of the SPs. Considering the strong coupling regime, i.e., the SP-QE interaction rate exceeds system dissipation rates, we find a critical SP-QE coupling attributed to the phase transition between normal and lasing steady states. Examining fluctuations above the system's steady states, we predict new elementary excitations, namely, the exciton-plasmon polaritons formed by the two-SP quanta and single-exciton states of QEs. The contribution of two-SP quanta results in the linear scaling of the SP-QE interaction rate with the number of QEs,No, as opposed to the√No-scaling known for the Dicke and Tavis-Cummings models. We further examine how SP-QE interaction scaling affects the polariton dispersions and power spectra in the vicinity of the critical coupling. For this purpose, we compare the calculation results assuming a finite ensemble of QEs and the model thermodynamic limit. The calculated power spectra predict an interplay of coherent photon emission by QEs near the second-harmonic frequency and correlated photon-pair emission at the fundamental frequency by the SPs (i.e., the photonic DPDC effect).