TY  - JOUR
A1  - Wyborski, Paweł
A1  - Musiał, Anna
A1  - Mrowiński, Paweł
A1  - Podemski, Paweł
A1  - Baumann, Vasilij
A1  - Wroński, Piotr
A1  - Jabeen, Fauzia
A1  - Höfling, Sven
A1  - Sęk, Grzegorz
T1  - InP-substrate-based quantum dashes on a DBR as single-photon emitters at the third telecommunication window
JF  - Materials
N2  - We investigated emission properties of photonic structures with InAs/InGaAlAs/InP quantum dashes grown by molecular beam epitaxy on a distributed Bragg reflector. In high-spatial-resolution photoluminescence experiment, well-resolved sharp spectral lines are observed and single-photon emission is detected in the third telecommunication window characterized by very low multiphoton events probabilities. The photoluminescence spectra measured on simple photonic structures in the form of cylindrical mesas reveal significant intensity enhancement by a factor of 4 when compared to a planar sample. These results are supported by simulations of the electromagnetic field distribution, which show emission extraction efficiencies even above 18% for optimized designs. When combined with relatively simple and undemanding fabrication approach, it makes this kind of structures competitive with the existing solutions in that spectral range and prospective in the context of efficient and practical single-photon sources for fiber-based quantum networks applications.
KW  - single-photon emitter
KW  - III–V quantum dot
KW  - telecommunication spectral range
KW  - photonic structure
KW  - extraction efficiency
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228773
SN  - 1996-1944
VL  - 14
IS  - 4
ER  - 
TY  - JOUR
A1  - Wurdack, Matthias
A1  - Lundt, Nils
A1  - Klaas, Martin
A1  - Baumann, Vasilij
A1  - Kavokin, Alexey V.
A1  - Höfling, Sven
A1  - Schneider, Christian
T1  - Observation of hybrid Tamm-plasmon exciton-polaritons with GaAs quantum wells and a MoSe\(_{2}\) monolayer
JF  - Nature Communications
N2  - Strong light matter coupling between excitons and microcavity photons, as described in the framework of cavity quantum electrodynamics, leads to the hybridization of light and matter excitations. The regime of collective strong coupling arises, when various excitations from different host media are strongly coupled to the same optical resonance. This leads to a well-controllable admixture of various matter components in three hybrid polariton modes. Here, we study a cavity device with four embedded GaAs quantum wells hosting excitons that are spectrally matched to the A-valley exciton resonance of a MoSe\(_{2}\) monolayer. The formation of hybrid polariton modes is evidenced in momentum resolved photoluminescence and reflectivity studies. We describe the energy and k-vector distribution of exciton-polaritons along the hybrid modes by a thermodynamic model, which yields a very good agreement with the experiment.
KW  - two-dimensional materials
KW  - microresonators
KW  - nanophotonics and plasmonics
KW  - cavity device
KW  - strong coupling
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170480
VL  - 8
IS  - 259
ER  - 
TY  - JOUR
A1  - He, Yu-Ming
A1  - Iff, Oliver
A1  - Lundt, Nils
A1  - Baumann, Vasilij
A1  - Davanco, Marcelo
A1  - Srinivasan, Kartik
A1  - Höfling, Sven
A1  - Schneider, Christian
T1  - Cascaded emission of single photons from the biexciton in monolayered WSe\(_{2}\)
JF  - Nature Communications
N2  - Monolayers of transition metal dichalcogenide materials emerged as a new material class to study excitonic effects in solid state, as they benefit from enormous Coulomb correlations between electrons and holes. Especially in WSe\(_{2}\), sharp emission features have been observed at cryogenic temperatures, which act as single photon sources. Tight exciton localization has been assumed to induce an anharmonic excitation spectrum; however, the evidence of the hypothesis, namely the demonstration of a localized biexciton, is elusive. Here we unambiguously demonstrate the existence of a localized biexciton in a monolayer of WSe\(_{2}\), which triggers an emission cascade of single photons. The biexciton is identified by its time-resolved photoluminescence, superlinearity and distinct polarization in micro-photoluminescence experiments. We evidence the cascaded nature of the emission process in a cross-correlation experiment, which yields a strong bunching behaviour. Our work paves the way to a new generation of quantum optics experiments with two-dimensional semiconductors.
KW  - lasers
KW  - LED
KW  - quantum dots
KW  - light sources
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-169363
VL  - 7
ER  -