Coherent Exciton-surface Plasmon Polariton Interactions In Hybrid Metal Semiconductor Nanostructures

摘要

We report on an experimental study of the optical properties of a metal-semiconductor hybrid structure consisting of a gold grating on a GaAs quantum well (QW). Our experiments reveal a coherent coupling between the surface plasmon polaritons (SPP) excited on a metal grating and the QW excitons. The hybrid structure is designed to optimize the radiative exciton-SPP interaction which is probed by low-temperature, angle-resolved far-field reflection spectroscopy. As a result of the coupling, a significant shift of ～ 7 meV and an increase in broadening by ～ 4 meV of the QW exciton resonance are observed. The results are explained with the help of a phenomeno-logical two layered model, predicting coupling strengths as large as 30 me V. Such a strong interaction can, e.g. be used to enhance the luminescence yield of semiconductor quantum structures or to amplify SPP waves.rnExperimentally measured angle-resolved low temperature reflectivity spectra of a multilayered metal-semiconductor hybrid nanostructure. The spectra are obtained after subtracting the SPP contribution and reveal a clear shift of the resonance and a slight change in the radiative damping of the heavy hole (HH) and light hole (LH) QW resonances as a result of the coherent coupling between the two resonances. Red dash-dotted lines indicate the SPP, QW and substrate dispersions.