Spontaneous emission enhancement in strain-induced WSe2 monolayer based quantum light sources on metallic surfaces

Atomic monolayers of transition metal dichalcogenides represent an emerging material platform for the implementation of ultra compact quantum light emitters via strain engineering. In this framework, we discuss experimental results on creation of strain induced single photon sources using a WSe2 monolayer on a silver substrate, coated with a very thin dielectric layer. We identify quantum emitters which are formed at various locations in the sample. The emission is highly linearly polarized, stable in linewidth and decay times down to 300 ps are observed. We provide numerical calculations of our monolayer-metal device platform to assess the strength of the radiative decay rate enhancement by the presence of the plasmonic structure. We believe, that our results represent a crucial step towards the ultra-compact integration of high performance single photon sources in nanoplasmonic devices and circuits

Resonance fluorescence from an atomic-quantum-memory compatible single photon source based on GaAs droplet quantum dots

This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 721394. We furthermore gratefully acknowledge support by the State of Bavaria.Single photon sources, which are compatible with quantum memories are an important component of quantum networks. In this article, we show optical investigations on isolated GaAs/Al0.25Ga0.75As quantum dots grown via droplet epitaxy, which emit single photons on resonance with the Rb-87-D2 line (780 nm). Under continuous wave resonant excitation conditions, we observe bright, clean and narrowband resonance fluorescence emission from such a droplet quantum dot. Furthermore, the second-order correlation measurement clearly demonstrates the single photon emission from this resonantly driven transition. Spectrally resolved resonance fluorescence of a similar quantum dot yields a linewidth as narrow as 660 MHz (2.7 μeV ), which corresponds to a coherence time of 0.482 ns. The observed linewidth is the smallest reported so far for strain free GaAs quantum dots grown via the droplet method. We believe that this single photon source can be a prime candidate for applications in optical quantum networks.PostprintPeer reviewe

Spontaneous emission enhancement in strain-induced WSe2 monolayer-based quantum light sources on metallic surfaces

Funding: State of Bavaria; H2020 European Research Council (ERC) (Project Unlimit-2D).Atomic monolayers of transition metal dichalcogenides represent an emerging material platform for the implementation of ultracompact quantum light emitters via strain engineering. In this framework, we discuss experimental results on creation of strain induced single photon sources using a WSe2 monolayer on a silver substrate, coated with a very thin dielectric layer. We identify quantum emitters that are formed at various locations in the sample. Their emission is highly linearly polarized, stable in linewidth, and decay times down to 100 ps are observed. We provide numerical calculations of our monolayer-metal device platform to assess the strength of the radiative decay rate enhancement by the presence of the plasmonic structure. We believe that our results represent a crucial step toward the ultracompact integration of high performance single photon sources in nanoplasmonic devices and circuits.PostprintPeer reviewe

Deterministic coupling of quantum emitters in WSe2 monolayers to plasmonic nanocavities

Funding: State of Bavaria, European Research Council [with the project unLiMIt2D (679228)]; National Research Foundation of Korea, Korean Government Grant (NRF-2016R1C1B2007007); National Science Foundation (DMR-1552220[, DMR-1838443]).We discuss coupling of site-selectively induced quantum emitters in exfoliated monolayers of WSe2 to plasmonic nanostructures. Gold nanorods of 20 nm-240 nm size, which are arranged in pitches of a few micrometers on a dielectric surface, act as seeds for the formation of quantum emitters in the atomically thin materials. We observe characteristic narrow-band emission signals from the monolayers, which correspond well with the positions of the metallic nanopillars with and without thin dielectric coating. Single photon emission from the emitters is confirmed by autocorrelation measurements, yielding g2(τ = 0) values as low as 0.17. Moreover, we observe a strong co-polarization of our single photon emitters with the frequency matched plasmonic resonances, as a consequence of light-matter coupling. Our work represents a significant step towards the scalable implementation of coupled quantum emitter-resonator systems for highly integrated quantum photonic and plasmonic applications.Publisher PDFPeer reviewe

Terahertz transmission through rings of quantum dots-nanogap

We report resonant funneling of terahertz (THz) waves through (9 +/- 1) nm wide quantum dots-nanogap of cadmium selenide quantum dots silver nanogap metamaterials. We observed a giant THz intensity enhancement (similar to 10(4)) through the quantum dots-nanogap at the resonant frequency. We, further report the experimentally measured effective mode indices for these metamaterials. A finite difference time domain simulation of the nanogap enabled by the quantum dots supports the experimentally measured THz intensity enhancement across the nanogap. We propose that these low effective mode index terahertz resonators will be useful as bio/chemical sensors, gain-enhanced antennas, and wave guides

Resonance fluorescence from an atomic-quantum-memory compatible single photon source based on GaAs droplet quantum dots

Single photon sources, which are compatible with quantum memories are an important component of quantum networks. In this article, we show optical investigations on isolated GaAs/Al0.25Ga0.75As quantum dots grown via droplet epitaxy, which emit single photons on resonance with the Rb-87-D2 line (780 nm). Under continuous wave resonant excitation conditions, we observe bright, clean and narrowband resonance fluorescence emission from such a droplet quantum dot. Furthermore, the second-order correlation measurementclearly demonstrates the single photon emission from this resonantly driven transition. Spectrally resolved resonance fluorescence of a similar quantum dot yields a linewidth as narrow as 660 MHz (2.7 μeV ), which corresponds to a coherence time of 0.482 ns. The observed linewidth is the smallest reported so far for strain free GaAs quantum dots grown via the droplet method. We believe that this single photon source can be a prime candidate for applications in optical quantum networks

Deterministic coupling of quantum emitters in WSe₂ monolayers to plasmonic nanocavities

We discuss coupling of site-selectively induced quantum emitters in exfoliated monolayers of WSe2 to plasmonic nanostructures. Gold nanorods of 20 nm-240 nm size, which are arranged in pitches of a few micrometers on a dielectric surface, act as seeds for the formation of quantum emitters in the atomically thin materials. We observe characteristic narrow-band emission signals from the monolayers, which correspond well with the positions of the metallic nanopillars with and without thin dielectric coating. Single photon emission from the emitters is confirmed by autocorrelation measurements, yielding g2(τ = 0) values as low as 0.17. Moreover, we observe a strong co-polarization of our single photon emitters with the frequency matched plasmonic resonances, as a consequence of light-matter coupling. Our work represents a significant step towards the scalable implementation of coupled quantum emitter-resonator systems for highly integrated quantum photonic and plasmonic applications.</p

Spontaneous emission enhancement in strain-induced WSe₂ monolayer-based quantum light sources on metallic surfaces

Atomic monolayers of transition metal dichalcogenides represent an emerging material platform for the implementation of ultracompact quantum light emitters via strain engineering. In this framework, we discuss experimental results on creation of strain induced single photon sources using a WSe2 monolayer on a silver substrate, coated with a very thin dielectric layer. We identify quantum emitters that are formed at various locations in the sample. Their emission is highly linearly polarized, stable in linewidth, and decay times down to 100 ps are observed. We provide numerical calculations of our monolayer-metal device platform to assess the strength of the radiative decay rate enhancement by the presence of the plasmonic structure. We believe that our results represent a crucial step toward the ultracompact integration of high performance single photon sources in nanoplasmonic devices and circuits.</p