The fine spectral tuning of plasmon mode and quantum emitter coupling and itscomparison with the dark-hot resonances

Abstract

: Localization of incident fields into very small volumes (hot-spots) allows strong light-matter inter-actions at the hot spots. This makes path interference effects, Fano resonances, visible. Fano resonances can appear due to the coupling of a bright plasmon (i) to a longer lifetime dark plasmon mode or (ii) to a quantum object (QO) of a much longer lifetime. The second phenomenon provides a very important utility: the voltage tunability of the linear/nonlinear response. The level-spacing of the QO, such as defect-centers and quantum dots, are voltage-tunable which can make a sharp Fano resonance appear and disappear. Here, we compare the two phenomena by solving the equations of motions for the near-field plasmon amplitudes, derived from two different Hamiltonians. While the two plasmon amplitudes look similar to each other, except for the population inversion parameter ‘ y ’, our results show that quantum emitter enables fine spectral tuning of the plasmon amplitude, thus, providing better enhancement.