Doctor of Philosophy (PhD)
Physics and Astronomy Department
The aim of this thesis is to highlight applications of quantum optics in two very distinct fields: space-based quantum communication and the Hawking effect in analogue gravity. Regarding the former: We simulate and analyze a constellation of satellites, equipped with entangled photon-pair sources, which provide on-demand entanglement distribution ser- vices to terrestrial receiver stations. Satellite services are especially relevant for long-distance quantum-communication scenarios, as the loss in satellite-based schemes scales more favor- ably with distance than in optical fibers or in atmospheric links, though establishing quantum resources in the space-domain is expensive. We thus develop an optimization technique which balances both the number of satellites in the constellation and the entanglement-distribution rates that they provide. Comparisons to ground-based quantum-repeater rates are also made. Overall, our results suggest that satellite-based quantum networks are a viable option for establishing the backbone of future quantum internet. Regarding the latter: The Hawking effect was discussed in the astrophysical context of the spontaneous decay of black holes into blackbody radiation, i.e. Hawking radiation. However, this effect seems to be universal, appearing anywhere that an event horizon (a region which restricts the flow of information to one direction) forms. Here, we analyze the Hawking effect in an optical-analogue gravity system, building on prior theoretical results regarding this effect in dielectric media. We provide a simplification of the process via the Bloch- Messiah decomposition, which allows us to decompose the Hawking effect into a discrete set of elementary processes. With this simplification and utilizing a popular entanglement measure (the logarithmic negativity), we examine the quantum correlations of the stimulated Hawking effect, explicitly showing that an environmental background temperature, along with backscattering, can lead to entanglement “sudden-death", even when the number of entangled Hawking-pairs is comparatively large. We also discuss the prospect of enhancing and “reviving" entanglement using single-mode, non-classical resources at the input. Though much of the discussion is phrased in terms of an optical-analogue model, the methods used and results obtained apply just as well to a variety of other systems supporting this effect. Finally, we provide decompositions of more exotic scenarios consisting of e.g. a white-hole– black-hole pair which share an interior region.
Brady, Anthony, "Applications of Quantum Optics: From the Quantum Internet to Analogue Gravity" (2021). LSU Doctoral Dissertations. 5484.