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Integrated Photonics for Quantum Optics

Time: Fri 2022-06-10 15.00

Location: U61, Brinellvägen 26, Stockholm

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Language: English

Subject area: Optics and Photonics Physics

Doctoral student: Samuel Gyger , Kvant- och biofotonik, Kvantnanofotonik, Quantum Nano Photonics

Opponent: Matthew D. Shaw, Jet Propulsion Laboratory, California Institute of Technology, USA

Supervisor: Val Zwiller, Kvant- och biofotonik; Stephan Steinhauer, Kvant- och biofotonik; Ali W. Elshaari, Kvant- och biofotonik; Marijn A. M. Versteegh, Kvant- och biofotonik

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Quantum physics allows us a vision of Nature's forces that bind the world, all its seeds and sources. After decades of primarily scientific research, we've arrived at a stage in time where quantum technology can be applied to practical problems and add value outside the field. Four pillars of quantum technologies are commonly identified: quantum computing, quantum simulation, quantum communication, and quantum sensing. For example, quantum computers will allow us to model quantum systems beyond our current capabilities, and quantum communication allows us to protect information unconditionally based on physics. Quantum sensing will enable us to measure our reality beyond classical limits.

Within all of these areas, optical photons play a unique role. In quantum computer implementations (e.g. photonic, trapped ion, or superconducting) photons can serve as a computational resource, for system read-out, or for linking distant hardware nodes. Quantum communication can only be realized via photons, utilizing the low-loss propagation of photons in optical fibers, on photonic devices as well as in free space. In quantum sensing and metrology, squeezed light can be used to go beyond the current limits of sensing methods. Therefore, the quantum technology field crucially relies on precise and efficient methods to generate, steer, manipulate and detect photons.

This dissertation discusses work in integrated photonic circuits, self-assembled semiconductor quantum dot devices, and superconducting nanowire single--photon detectors.

We integrate multiple materials on a silicon nitride platform, including Cu2O as a platform for solid-state Rydberg physics, WS2 to improve non-linear light-generation within Si3N4, and hBN as an excellent single-photon emitter.We demonstrate optically active quantum dots as single-photon emitters in the telecom C-band and their compatibility with commercial telecom equipment.We strain-control the fine-structure splitting of these devices, which is required for future quantum interference-based protocols.

Finally, we study superconducting nanowire single-photon detectors (SNSPD) and combine them with photonic micro-electromechanical systems (MEMS), establishing a cryo-compatible, reconfigurable photonic platform.