Quantum Communications with Near-Term Quantum Networks

Abstract

Quantum networks promise to enable provably secure communications, enhanced sensing, enhanced imaging and distributed quantum information processing. However, low generation rates and the quality of distributed entanglement will constrain near-term quantum networks. This dissertation explores near-term quantum networks for shared entanglement generation. We begin by reviewing the theoretical limits of quantum communications and the principles underlying quantum links and repeaters, including various photon-based and memory qubit encodings. We then analyze quantum link architectures for entanglement generation for a diverse class of photonic encodings. We subsequently analyze linear-chain quantum repeater networks; we discuss improvements to the rate-vs.-loss scaling with time-multiplexed entanglement swaps and the practical limitations associated with finite memory coherence times and buffer capacities. We propose satellite-assisted quantum links as an alternative to quantum repeaters, presenting and analyzing several candidate link architectures.