39 research outputs found
Raman scattering excitation spectroscopy in monolayer WS
Resonant Raman scattering is investigated in monolayer WS at low
temperature with the aid of an unconventional spectroscopy technique, ,
Raman scattering excitation (RSE). The RSE spectrum is made up by sweeping the
excitation energy, when the detection energy is fixed in resonance with
excitonic transitions related to neutral and/or charged excitons. We
demonstrate that the shape of the RSE spectrum strongly depends on a selected
detection energy. The out-going resonance with the neutral exciton leads to an
extremely rich RSE spectrum displaying several Raman scattering features not
reported so far, while no clear effect on the associated background
photoluminescence is observed. Instead, a strong enhancement of the emission
due to the negatively charged exciton is apparent when the out-going photons
resonate with this exciton. Presented results show that the RSE spectroscopy
can be a useful technique to study electron-phonon interactions in thin layers
of transition metal dichalcogenides.Comment: 9 pages, 5 figure
Non-linear exciton spin-splitting in single InAs/GaAs self-assembled quantum structures in ultrahigh magnetic fields
We report on the magnetic field dispersion of the exciton spin-splitting and
diamagnetic shift in single InAs/GaAs quantum dots (QDs) and dot molecules
(QDMs) up to = 28 T. Only for systems with strong geometric confinement,
the dispersions can be well described by simple field dependencies, while for
dots with weaker confinement considerable deviations are observed: most
importantly, in the high field limit the spin-splitting shows a non-linear
dependence on , clearly indicating light hole admixtures to the valence band
ground state
International Consensus Statement on Rhinology and Allergy: Rhinosinusitis
Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICARâRS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICARâRSâ2021 as well as updates to the original 140 topics. This executive summary consolidates the evidenceâbased findings of the document. Methods: ICARâRS presents over 180 topics in the forms of evidenceâbased reviews with recommendations (EBRRs), evidenceâbased reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICARâRSâ2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidenceâbased management algorithm is provided. Conclusion: This ICARâRSâ2021 executive summary provides a compilation of the evidenceâbased recommendations for medical and surgical treatment of the most common forms of RS
Charged and neutral excitons in natural quantum dots in the InAs/GaAs wetting Layer
Magnetospectroscopic studies of the InAs/GaAs wetting layer (WL) accompanying self-organized quantum dots (QDs) grown in Stranski\u2013Krastanow mode are presented. Sharp emission lines from \u201cnatural\u201d QDs formed in the WL are observed and their evolution in magnetic field is investigated. A quadruplet or a doublet splitting of the emission lines has been observed in magnetic field, which is attributed to a charged and a neutral exciton in a single dot. The metastable transformation of the spectrum from the former to the latter configuration has been observed and explained in terms of the charging of a single dot.Peer reviewed: YesNRC publication: Ye
Localization of Excitons in the Wetting Layer Accompanying Self-Assembled InAs/GaAs Quantum Dots
NRC publication: Ye
Emission from a highly excited single InAs-GaAs quantum dot in magnetic fields: An excitonic Fock-Darwin diagram
NRC publication: Ye