Fig. 2: Coupling between chiral plasmon resonance and single quantum emitters.
From: Revealing broken valley symmetry of quantum emitters in WSe2 with chiral nanocavities
a Optical microscope image of monolayer (ML) WSe2 covered on the plasmonic lattices L1, 2, 3, 4 with different periods and sizes. Scale bar, 10 μm. b SEM images of plasmonic lattices in a. Scale bar, 250 nm. Here, the period of L1 is 400 nm and the period of L2, 3, 4 is 450 nm. c Measured reflection spectra of plasmonic lattices. The inset shows enlarged CPR of L1, 2, 3, 4. d The photoluminescence (PL) spectra of the hybrid structures and monolayer on indium tin oxide (ITO) substrate at room temperature. Inset, corresponding PL mapping at 1.65 eV with an intensive PL enhancement at L1 due to the resonance of excitons with plasmon mode. Scale bar, 10 μm. e, Low-temperature (4.2 K) PL spectra of monolayer flake on lattice structures and substrates. f Enlarged PL spectrum with massive sharp emission lines at L1 region. g The linewidth statistical histogram of the different sharp peaks with values less than 260 μeV, indicating the formation of quantum emitters.
