On noise in swap ASAP repeater chains: exact analytics, distributions and tight approximations

27 August 2024

Title: On noise in swap ASAP repeater chains: exact analytics, distributions and tight approximations

Speaker: Dr. Kenneth Goodenough, University of Massachusetts

Abstract of Talk: Losses in fibres are one of the main bottlenecks for the distribution of entanglement in quantum networks, which can be overcome by the implementation of quantum repeaters. The most basic form of a quantum repeater chain is the swap ASAP repeater chain. Fully characterizing the (average) quality of the entanglement as the repeater chain grows is still an open problem. Here, we close this gap by providing a so-called generating function, a function whose Maclaurin series encodes the solutions for repeater chains for all possible lengths. We furthermore find simple approximations of the average fidelity that are exponentially tight, and, for up to 10 segments, the full distribution of the delivered fidelity. The talk is aimed to be accessible to people outside of the small but friendly quantum repeater community.

Profile of Speaker: Kenneth Goodenough is a postdoctoral researcher in quantum communication theory at the University of Massachusetts, Amherst. During his PhD with David Elkouss at QuTech he has worked on near-term repeater schemes, distillation and error correction. His main interest is in better understanding what can be done with near-term quantum devices, mostly through studying mathematical structures behind noisy quantum systems. This includes graph states, stabilizer codes, entanglement distribution schemes and their associated combinatorics.