Selectively Addressing Plasmonic Modes and Excitonic States in a Nanocavity Hosting a Quantum Emitter

Abstract

Controlling the interaction between the excitonic states of a quantum emitter and the plasmonic modes of a nanocavity is key for the development of quantum information processing devices. In this Letter we demonstrate that the tunnel electroluminescence of electrically insulated C 60 nanocrystals enclosed in the plasmonic nanocavity at the junction of a scanning tunneling microscope can be switched from a broad emission spectrum, revealing the plasmonic modes of the cavity, to a narrow band emission, displaying only the excitonic states of the C 60 molecules by changing the bias voltage applied to the junction. Interestingly, excitonic emission dominates the spectra in the high-voltage region in which the simultaneously acquired inelastic rate is low, demonstrating that the excitons cannot be created by an inelastic tunnel process. These results point toward new possible mechanisms for tunnel electroluminescence of quantum emitters and offer new avenues to develop electrically tunable nanoscale light sources.

Imaging Strain-Localized Single-Photon Emitters in Layered GaSe below the Diffraction Limit

“…Plane-wave DFT calculations were carried out using the Vienna Ab initio Simulation Package , (VASP) with projector augmented wave (PAW) pseudopotentials ,, for electron–ion interactions, and the generalized gradient approximation (GGA) functional of Perdew, Burke, and Ernzerhof (PBE) for exchange–correlation interactions. The details of geometry optimization of bulk GaSe were shown in our previous work .…”

“…For example, cathodoluminescence (CL) − microscopy has been used to study defect-related SPEs in 2D hBN. Tip-enhanced photoluminescence (PL) − and scanning tunneling luminescence microscopies have been used to study localized emitters in quantum dots, carbon nanotubes, and monolayer WSe 2 . Compared to the other techniques, CL microscopy provides an approach to performing noncontact measurements at low temperatures with exceptional selectivity in identifying specific areas of interest and compatibility with photon antibunching measurements.…”