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Abstract

Department of PhysicsAbstract Quantum light arises as a key hardware to construct quantum information process based on distinctive quantum phenomena from classical aspect such as superposition, entanglement and no-cloning theorem. In particular, the photons as a quantum particle enable us to encode quantum information using various degrees of freedom such as their time-bin, path, spin/orbital angular momentums, and so on. Also as a flying qubit, they can deliver quantum information over long distance. With recent progress on quantum technology, however, their realization requires the quantum light emitters with better performances. Recently, there have been numerous researches of quantum emitters. In the case of solid-state quantum emitters, they can be fabricated in mesoscopic scale without any large-scale complex setups, which contributes to integration with other photonics platforms. Some materials for the solid-state quantum emitters supports an electrical operation such as excitation pump, and it is easy to engineer the emitter platforms with controlling emitter???s size and strain. Also, they do not require extremely low temperature at the order of millikelvin, which is required for the other quantum platforms such as atoms and superconducting qubits. Together with deterministic generation of single photons with high performance, for achieving scalable quantum system, it is becoming more important to spectrally and spatially couple the single quantum emitters with other quantum emitters or various photonic structures such as cavities and waveguides. However, the randomness of the emitter???s positions and emission frequency between the emitters give rise to steep challenges. To overcome these problems, numerous researches were proceeded but simultaneous control of position and frequency cannot still be achieved yet. Atomically thin two-dimensional materials have fascinated for their flexibility and electrical operations. In addition, 2D materials are generally sensitive to external force, which is good at deforming their band structure. Using the above advantages in two-dimensional materials, it is possible to realize on-demand single photons with controlled position and frequency. In this thesis, our experiment realized the controlling position and the emission frequency of single photon emitters based on an atomically thin tungsten diselenide layer (WSe2) with local strain engineering. To control the position of quantum emitters, we have defined a pyramidal nano-patterns as local strain-inducing structures on a silicon substrate and transferred the 2D WSe2 on the patterned substrate. Indeed, we have confirmed the antibunching property of the single photons from the quantum emitters on interested positions. To control the emission frequency of the quantum emitters, we developed a local strain manipulating system (membrane actuator) around the site-controlled emitters. The frequency modulation could be achieved by controlling the electrostatic field of the actuators changing the degree of the strain. Therefore, we successfully demonstrated solid-state single photon emitters with controlled position and frequency. We believe this approach makes a milestone for realization of scalable quantum photonic platforms and flexible application with quantum photonics.clos