Quantum Sensors: A Comprehensive Review and Future Perspectives
Quantum sensing is an emerging field that exploits the principles of quantum mechanics to achieve unprecedented levels of precision, sensitivity, and accuracy in measuring physical quantities. From navigation and artificial intelligence to environmental monitoring and medical diagnostics, these technologies have the potential to transform a wide range of applications completely. This review provides an exploration of the fundamental principles, state-of-the-art developments, and future perspectives of quantum sensors and perception. We discuss the underlying quantum phenomena, such as superposition, entanglement, and quantum coherence, and their role in enabling advanced sensing capabilities. We also look at how quantum sensors can be incorporated into several applications. Lastly, we address the field’s challenges and outline future research directions.
Network Design in Multiple Non-Overlapping Paths within Quantum Key Distribution Networks
The increasing demand for secure communication makes quantum key distribution (QKD) a compelling technology, as it exploits the fundamental principles of quantum physics to enhance secure data transmission. However, practical deployment faces limitations such as limited transmission distances and dedicated hardware-channel requirements. This paper proposes a linear programming-based model that jointly addresses routing, wavelength assignment, and trusted-node minimization in QKD networks with wavelength division multiplexing (WDM), considering that the secret key rate becomes impractical beyond a given transmission distance, thus requiring the relaying of secret keys through trusted repeaters. In particular, the study contrasts scenarios where traffic is concentrated along a single route with those where key rates are split and routed over multiple nonoverlapping paths (MNOPs) using two mechanisms: Concatenate Multipart (CM) and Bitwise Product Multipath (BPM). While the literature shows that MNOPs can improve security (BPM) and improve the secret key rate (CM), we demonstrate that these mechanisms come with additional deployment costs.