Basics of quantum plasmonics

Abstract

The present work is a topical review of the theoretical research on the quantum theory of plasmons and plasmon-photon interaction. The plasmons are defined as the quanta of the quantized plasmonic field. The corresponding classical plasmonic field was constructed on the basis of the study of collective oscillations of the electron gas in the solid. The electron-electron Coulomb interaction is taken into account. The explicit forms of the plasmon-photon interaction Lagrangian in canonical quantum mechanics and the plasmon-photon interaction action functional in the functional integral approach are derived. They all show that the interaction processes are nonlocal ones. The physical origin of the nonlocality is the complex structure of plasmons as composite quasiparticles: they cannot be considered as point particles, as was assumed in all phenomenological theories.