Periodic Reporting for period 1 - HELPS (High efficient localized photon sources)
Période du rapport: 2021-03-15 au 2023-03-14
Quantum emitters as single-photon sources (SPSs) are required elements for the realization of scalable quantum photonics systems for secure communication and quantum networking. They can be formed in wide bandgap semiconductors by individual deep defects. Ideally, these sources produce single-photon states with 100% probability at a time, multi-photon states with 0% probability and should emit single indistinguishable photons. During the last years, significant progress has been observed in the fabrication, manipulation and characterization of SPSs by engineering an optimal electromagnetic environment for single-photon emitters. Nevertheless, despite some achieved advances, just a few research groups have been able to generate quantum light on-chip using quantum dots. Furthermore, one of the major challenges of SPSs still remains open: their deterministic integration in photonic systems for complex quantum technologies with full control of on-demand single-photon emission. Within this framework, the beneficiary has addressed these challenges through the development of various hybrid and scalable quantum photonic approaches.
From the quantum point of view, two-dimensional (2D) materials provide a path for driving nanophotonics into the atomic scale because of their unique optical response and low dimensionality. Their mechanical properties allow them to be transferred onto any type of surface and their optical properties are very interesting. It is well known that 2D materials such as transition metal dichalcogenides (TMDCs) monolayers show extraordinary physical and chemical properties, including thickness-dependent bandgaps, high carrier mobility, wide optical absorption, high optical response, etc. On the other side, layered materials such as hexagonal Boron Nitride and TMDCs can directly host color centers (quantum emitters) by impurities or defects, and their quantum emission ranges from the visible (VIS) to the near-infrared (NIR). In those cases, their single-photon emission is very sensitive to environmental factors, such as strain or dielectric surroundings, making them ideal for deterministic coupling in plasmonic nanocavities and strain engineering.
In this project, we developed new approaches based on metasurfaces and strain engineering for stable quantum emission by using hyperbolic Meta-Antennas arrays. The coupling to nano-antennas can be used to strongly enhance the quantum yield in TMDs via the enhancement of the radiative decay rate, emphasizing the potential of this approach for light-emitting device applications. Our findings revealed that these artificially engineered planar materials are optimal electromagnetic environments to generate, control and manipulate quantum emitters from atomically thin layers. The results of the project will push quantum technology to extreme enhancement of emission light which will provide new opportunities for the development of quantum encryption, as well as quantum computers.
From the quantum point of view, two-dimensional (2D) materials provide a path for driving nanophotonics into the atomic scale because of their unique optical response and low dimensionality. Their mechanical properties allow them to be transferred onto any type of surface and their optical properties are very interesting. It is well known that 2D materials such as transition metal dichalcogenides (TMDCs) monolayers show extraordinary physical and chemical properties, including thickness-dependent bandgaps, high carrier mobility, wide optical absorption, high optical response, etc. On the other side, layered materials such as hexagonal Boron Nitride and TMDCs can directly host color centers (quantum emitters) by impurities or defects, and their quantum emission ranges from the visible (VIS) to the near-infrared (NIR). In those cases, their single-photon emission is very sensitive to environmental factors, such as strain or dielectric surroundings, making them ideal for deterministic coupling in plasmonic nanocavities and strain engineering.
In this project, we developed new approaches based on metasurfaces and strain engineering for stable quantum emission by using hyperbolic Meta-Antennas arrays. The coupling to nano-antennas can be used to strongly enhance the quantum yield in TMDs via the enhancement of the radiative decay rate, emphasizing the potential of this approach for light-emitting device applications. Our findings revealed that these artificially engineered planar materials are optimal electromagnetic environments to generate, control and manipulate quantum emitters from atomically thin layers. The results of the project will push quantum technology to extreme enhancement of emission light which will provide new opportunities for the development of quantum encryption, as well as quantum computers.
During the reporting period, the design, simulation and nanofabrication of different metasurfaces were developed for the enhancement of the light-matter properties of 2D materials coupled to them.
The metasurfaces were first modeled by using Johnson and Christy material data from the in-build material library of Ansys Lumerical. The metasurfaces fabricated were based on:
1) Silver nanoparticle on top of hBN layer separated by 20nm SiO2 layer over gold mirror (100nm).
2) Hyperbolic Met-Antenna array of three alternative layers of Au (20nm) and SiO2 (20nm) with a diameter ranging from 100-200nm
The simulation was performed to enhance the optical properties of suitable 2D materials. In particular; transition metal dichalcogenides such as WSe2 and hexagonal Boron Nitride (hBN).
All these materials were thoroughly studied and characterized before the photonic integration. For example, using a combination of experiment (via Photoluminescence, PL) and theory (DFT), we elucidated the effect of the dielectric environment on defect properties in hBN.
The deterministic integration of the 2D materials was performed by using a combination of wet and dry transfer techniques. We also developed a novel method to transfer the selected material to the metasurface based on PVA and PPC polymers using different temperatures.
Finally, we demonstrated the enhancement of the light-matter properties for the hybrid structures by the optical characterization and analysis of the Purcell enhancement via the analysis PL dynamics, single photon emission and characterization of the localized excitons under strong magnetic fields. With these Hybrid structures, we also generate quantum emitters by strain engineering.
The metasurfaces were first modeled by using Johnson and Christy material data from the in-build material library of Ansys Lumerical. The metasurfaces fabricated were based on:
1) Silver nanoparticle on top of hBN layer separated by 20nm SiO2 layer over gold mirror (100nm).
2) Hyperbolic Met-Antenna array of three alternative layers of Au (20nm) and SiO2 (20nm) with a diameter ranging from 100-200nm
The simulation was performed to enhance the optical properties of suitable 2D materials. In particular; transition metal dichalcogenides such as WSe2 and hexagonal Boron Nitride (hBN).
All these materials were thoroughly studied and characterized before the photonic integration. For example, using a combination of experiment (via Photoluminescence, PL) and theory (DFT), we elucidated the effect of the dielectric environment on defect properties in hBN.
The deterministic integration of the 2D materials was performed by using a combination of wet and dry transfer techniques. We also developed a novel method to transfer the selected material to the metasurface based on PVA and PPC polymers using different temperatures.
Finally, we demonstrated the enhancement of the light-matter properties for the hybrid structures by the optical characterization and analysis of the Purcell enhancement via the analysis PL dynamics, single photon emission and characterization of the localized excitons under strong magnetic fields. With these Hybrid structures, we also generate quantum emitters by strain engineering.
Taking into account the transfer of knowledge activities, the record of publications, the milestone and the deliverables produced, the overall objectives of the project were achieved., in particular, the deterministic generation of quantum emitters and new physical phenomena that arise from the coupling of semiconducting material with the engineered metasurfaces. These results are being formulated in the form of a manuscript and will be published soon. This project expects to pave the way for future work on non-classical light interaction with metasurfaces. The results of the HELPS project are expected to increase the understanding of the novel applications and functionalities of hyperbolic nanostructured metamaterials through the fabrication of several architectures for single-photon generation on-demand.