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A high-quality single-photon source (SPS) is one of the most critical components in photonic quantum information technologies (e.g. QKD, cryptography, linear quantum computing, etc.) where qubits are encoded within individual photons. Moreover, the scalability of these technologies relies heavily on their integration into existing photonic systems, so controlling their quantum properties is crucial. Besides their advantages, current material platforms present limitations due to their complex fabrication procedures and inherent attributes. In the search for reliable SPSs, Transition Metal Dichalcogenides (TMDCs) have emerged as a promising platform. Despite the recency of the field, they have exhibited satisfactory integration potential into photonic cavities, purity close to the state-of-the-art, and the ability to be used in quantum information protocols. The poster presents on-chip quantum emitters from monolayer WSe2 with controlled polarization and high purity, via strain and defect engineering. We explain the drawbacks of current nanopillar designs for strain application, which we use to justify the new proposed geometries. Moreover, we analyze the entire fabrication process from the structure fabrication, the flake exfoliation and transfer, to the defect introduction through electron beam irradiation. Finally, we characterize the samples with different imaging techniques and present the properties of the produced quantum emitters.

Photonic quantum information technologies, such as linear optical quantum computing and quantum communications, can be implemented using efficient single-photon sources, detectors, and ordinary linear optical elements to manipulate qubits, which are encoded onto single photons. Scalable quantum computing and communications with millions of qubits require many efficient sources providing indistinguishable and pure single-photon states to obtain entanglement and maximize security without additional protocol complexity. However, this has been proven to be very challenging due to the limitations of both the material platforms and the fabrication complexity. Transition-metal dichalcogenide (TMDC) flakes are among the most recently discovered platforms for quantum information. Still, they have already shown promising results in terms of single-photon emission purity of strained monolayers, deterministic integration of the single-photon emitters in nanophotonic devices, and competitive performance with other single-photon emitters for quantum key distribution. In this poster, we present our advancement toward generating, manipulating, and collecting single-photon states in photonic chips with TMDC devices on silica-on-silicon substrates. First, we justify and support the chosen designs with the results obtained with finite-difference numerical modeling. We then illustrate our nanofabrication process for the development of WSe2 and MoTe2 single-photon emitters, WS2 linear optical components (e.g., waveguides, beam splitters, and interferometers), and photonic crystal nanobeam cavities toward the efficient manipulation of pure and indistinguishable single photons. Finally, we report our preliminary results from the optical characterization experiments carried out so far.