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We measure low-temperature micro-photoluminescence spectra along a MoS 2 nanotube, which exhibit the peaks of the optical whispering gallery modes below the exciton resonance. The energy fluctuation and width of these peaks are determined by the changes of the nanotube wall thickness and propagation of the optical modes along the nanotube axis, respectively. We demonstrate the potential of the high-quality nanotubes for realization of the strong coupling between exciton and optical modes when the Rabi splitting can reach 400 meV. We show how the formation of exciton-polaritons in such structures will be manifested in the micro-photoluminescence spectra and analyze the conditions needed to realize that.

We report on comparative optical studies of InAs/Al0.44Ga0.56As quantum dots (QDs) grown by molecular beam epitaxy either with or without a thin GaAs interlayer inserted between the AlGaAs barrier and InAs QDs. Emission properties of individual QDs are investigated by micro-photoluminescence spectroscopy using 500-nm-size etched cylindric mesa structures. The single-photon statistics of the QDs of both types, emitting in the red spectral range between 636 and 750 nm, is confirmed by the measurements of the second-order correlation function. A negligibly small exciton fine structure splitting is detected in the majority of the QDs grown with the GaAs interlayer that implies the possibility of generating pairs of entangled photons with high entanglement fidelity.

Abstractauthoren We demonstrate that the selection of a limited number of single excitonic lines from a dense array of epitaxial quantum dots (QDs) can be realized spectrally via resonant energy transfer from a huge number of small QDs toward a limited set of large nano‐islands through their excited levels. Optical and transmission electron microscopy studies support this mechanism. Theoretical modeling describes the architecture of quantum levels in the array of CdSe/ZnSe QDs, which enables such a spectral selection. Schematic of resonant energy transfer between QDs shown together with a plan‐view TEM image of a QD array.

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