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Full-Text Articles in Physical Sciences and Mathematics
Non-Gaussian Measurements Of Coherent States Of Light For Metrology And Communication, Matthew Dimario
Non-Gaussian Measurements Of Coherent States Of Light For Metrology And Communication, Matthew Dimario
Physics & Astronomy ETDs
Conventional measurement technology is unable to extract the most amount of information possible from coherent states of light. Non-Gaussian measurements which can count individual photons can surpass the sensitivity limits of ideal conventional strategies, and approach the ultimate limits achievable given by quantum mechanics. This thesis presents investigations and demonstrations of these unconventional measurements, which utilize coherent operations and single photon counting. This thesis shows that non-Gaussian measurements can outperform conventional strategies in estimation tasks as well as a variety of communication problems. This thesis also investigates novel approaches and algorithms for building robustness to static and dynamic noise which …
Weak Measurements For Quantum Characterization And Control, Jonathan A. Gross
Weak Measurements For Quantum Characterization And Control, Jonathan A. Gross
Physics & Astronomy ETDs
This dissertation concerns itself with the virtues and vices of weak measurements. Weak measurements are all around us, but this does not mean that one should manufacture weakness on all occasions. We critically evaluate two proposals that claim weak measurements provide a novel means of performing quantum state tomography, allegedly increasing tomographic efficacy and yielding foundational insights into the nature of quantum mechanics. We find weak measurements are not an essential ingredient for most of their advertised features. In contrast to this negative finding, we highlight an optimal tomographic scheme for which weak continuous measurements are the best known implementation, …
Studies Of Light Generation With Four-Wave Mixing In A Cold Atomic Ensemble, Andrew Ferdinand
Studies Of Light Generation With Four-Wave Mixing In A Cold Atomic Ensemble, Andrew Ferdinand
Physics & Astronomy ETDs
Correlated light generated from atomic ensembles can have a central role in prominent quantum information protocols, such as long-distance quantum communication. Here we present our studies on three topics involving the generation of correlated light with four-wave mixing (FWM) in a cold atomic ensemble for applications in quantum communications with high capacity. We experimentally investigate the generation of light with seeded FWM in cold cesium atoms and the time correlations of photon pairs generated with spontaneous FWM. We theoretically investigate the correlations in orbital angular momentum of photon pairs generated with spontaneous FWM for a range of experimental geometries. These …