Fidelity-Guaranteed Entanglement Routing with Distributed Purification Planning
Abstract
Many quantum-network applications require end-to-end Bell pairs whose fidelity exceeds a request-specific threshold, but existing entanglement routing algorithms either optimize only throughput without regard for fidelity or enforce fidelity guarantees using centralized controllers with global link-state knowledge. We present Q-GUARD, an online entanglement routing algorithm that enforces per-request fidelity thresholds within a distributed protocol model in which nodes exchange link-state information only with their k-hop neighbors. After link outcomes are realized in each slot, Q-GUARD builds per-link purification cost tables from realized Bell pairs, allocates per-hop fidelity targets using a Werner-state equal-split rule, and selects between candidate path segments using a segment-local expected-goodput (EXG) metric that jointly accounts for swap success, purification overhead, and resource availability. We also introduce Q-GUARD-WS, an extension that exploits per-link hardware quality estimates to allocate purification effort non-uniformly across hops. On synthetic 100-node topologies with heterogeneous link fidelity and stochastic BBPSSW purification, Q-GUARD raises the qualified success rate from under 20\% to over 85\% on 4-hop paths and nearly doubles the qualified service radius in Euclidean distance relative to throughput-only and naive-purification baselines, while Q-GUARD-WS provides additional throughput gains under high hardware heterogeneity.
Related
- Entanglement Cost of Optimal Distributed Quantum State Purification
- Entanglement of purification for Werner states: canonical purification and nonadditivity
- Rényi Entanglement of Purification Is Non-additive
- Rényi-2 entanglement of purification of the symmetric Werner state
- Arbitrary high-dimensional entanglement purification with the superposition of paths
BibTeX
@misc{gatti2026fidelityguaranteed,
title = {{Fidelity-Guaranteed Entanglement Routing with Distributed Purification Planning}},
author = {Anthony Gatti and Anoosha Fayyaz and Prashant Krishnamurthy and Kaushik P. Seshadreesan and Amy Babay},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2605.00246},
eprint = {2605.00246},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.00246},
}
RIS
TY - UNPB
TI - Fidelity-Guaranteed Entanglement Routing with Distributed Purification Planning
AU - Anthony Gatti
AU - Anoosha Fayyaz
AU - Prashant Krishnamurthy
AU - Kaushik P. Seshadreesan
AU - Amy Babay
PY - 2026
DA - 2026/10/25
PB - arXiv
DO - 10.48550/arxiv.2605.00246
UR - https://arxiv.org/abs/2605.00246
AB - Many quantum-network applications require end-to-end Bell pairs whose fidelity exceeds a request-specific threshold, but existing entanglement routing algorithms either optimize only throughput without regard for fidelity or enforce fidelity guarantees using centralized controllers with global link-state knowledge. We present Q-GUARD, an online entanglement routing algorithm that enforces per-request fidelity thresholds within a distributed protocol model in which nodes exchange link-state information only with their k-hop neighbors. After link outcomes are realized in each slot, Q-GUARD builds per-link purification cost tables from realized Bell pairs, allocates per-hop fidelity targets using a Werner-state equal-split rule, and selects between candidate path segments using a segment-local expected-goodput (EXG) metric that jointly accounts for swap success, purification overhead, and resource availability. We also introduce Q-GUARD-WS, an extension that exploits per-link hardware quality estimates to allocate purification effort non-uniformly across hops. On synthetic 100-node topologies with heterogeneous link fidelity and stochastic BBPSSW purification, Q-GUARD raises the qualified success rate from under 20\% to over 85\% on 4-hop paths and nearly doubles the qualified service radius in Euclidean distance relative to throughput-only and naive-purification baselines, while Q-GUARD-WS provides additional throughput gains under high hardware heterogeneity.
ER -