Quantum Communications Systems.

摘要

This project supported research activities for making quantum- enhanced communications and metrology practical. The strategy was to develop robust photonic quantum states and sensors serving as an archetype for loss- tolerant information acquisition beyond the standard quantum limit, as well as in finding practical sensing applications outside the laboratory for detecting objects in situations where power-limited illumination is critical. Support from the US Air Force has allowed the University to establish integrated photonics as the most promising candidate for a robust implementation of quantum-enhanced optical sensors. In such a compact architecture, the challenge of achieving low-loss regime can be realistically met: convincing demonstrations of the viability of this strategy has been undertaken within the scope of this project. We have also been efficient in investigating fundamental issues of quantum metrology, establishing a general framework for understanding more complex scenarios, such as lossy parameter estimation, and joint measurements of multiple parameters. Investigations have fostered a novel approach which will inform our future researchers: the adoption of sensing networks in which quantum memories act as key devices. Their role will consist in both reconfigurable devices in sensing networks, as well as in synchronization elements of multiple single-photon sources, allowing, even with current devices, a dramatic enhancement in the number of photons realistically available in the experiment.