Loss Characterization in Quantum Networks

Research areas in quantum information science such as quantum key distribution, distributed quantum computing, and quantum sensing require the ability to exchange information between quantum devices. The first quantum network testbeds have already been created, and with continuous progress leading to further advancements, current focus falls on determining how to best characterize the quality of a given network. Quantum Network Tomography (QNT) aims to characterize errors within quantum network channels utilizing end-to-end measurements. We have previously developed QNT models to infer channel errors, particularly Pauli noise and depolarizing noise. Here we discuss recent work addressing erasure errors such as loss within quantum channels. Particularly, we introduce a new protocol for loss tomography which can be expanded to n-node star topologies, paving a pathway to applying a similar method to larger-scale networks in the future.